Cross stitch is easy. It's just two little stitches crossed over each other. See that?
Counted cross stitch is not worked onto fabric that has been pre-printed. Counted cross stitch uses special fabrics that are called evenweave fabrics. These fabrics are woven so that they have the same number of warp threads (or, the threads running lengthwise through the fabric) and the same number of weft threads (or, the threads running crosswise, from selvedge to selvedge). In counted cross stitch (and from here on out, I'll just call it cross stitch) you work each stitch over the grid of perfect squares made by the warp and weft threads of your fabric.
Cross stitch can be done on different kinds of evenweave fabric, including evenweave linen, some woven ginghams, Aida cloth (which has a very ponounced grid that helps you see the holes into which your stitches go), waste canvas (which is a removable grid you temporarily apply to a piece of non-evenweave fabric that helps you place your stitches), and various other types of fabrics made especially for cross stitching. The fiber content and type of weave of the fabric you choose to use is largely a matter of personal preference.
What really matters is the "count" of the fabric. Thread count refers to the number of warp and weft threads per inch in the woven fabric. Stitch count refers to the number of cross stitches per inch you will have in your finished design. Aida cloth, for instance, is labeled according to stitch count; 10-count Aida cloth gives you 10 stitches per inch. Evenweave linen, however, is labeled according to thread count; 28-[thread]-count evenweave linen will give you a stitch count of 14, since cross stitch on this kind of linen is worked over 2 warp threads horizontally, and 2 weft threads vertically.
Look very closely at the photo above and you can see the crossed stitches going over 2 threads in each direction.
Count is very important when choosing fabrics for cross stitching because the number of stitches per inch can drastically change the look of a design. In general, fabric with a lower stitch count will produce a coarser looking design, where the crosses will be larger and more pronounced. Fabric with a higher stitch count will produce designs that are smaller and finer. For the sampler pictured here, I used 28-count Cashel linen, which gives me 14 stitches per inch. Typically, 2 strands of embroidery floss are used on 28-count linen (or 14-count Aida). This is my favorite size of cross stitching, because the crosses are large enough to still look like crosses, and small enough to give detail without making me go blind. For cross stitching on evenweave linen, I use a large-eyed, blunt-tipped tapestry needle. I like a size 24 needle.
To work designs in cross stitch you follow a chart. Each colored box on the chart represents one set of crossed stitches. Each set of crossed stitches is relative to the other stitches in the design, so you're only ever "counting" a few stitches away from the last stitch you just made. Each color on the chart represents a specific color of six-strand embroidery floss. A color key helps you define each color of floss. If the chart is too small for you to see comfortably, just enlarge it on a color copier. A good full-spectrum lamp is a must in dim light. I use an Ott light.
Every design should tell you the dimensions of the design area, or the outermost edges of the stitching. For instance, the design I'm working here (my Winterwoods ABCs pattern), the design area is 111 stitches across by 140 stitches down, or approximately 8" x 10" on 28-count fabric. The fabric you use for any sampler should always be cut at 2-3" longer on all sides beyond the design area. This margin helps hold the fabric in the hoop when you are stitching motifs close to the edge of the design area, and also allows you to stretch the piece properly when it comes time to frame.
Facing a blank piece of fabric and unsure where to start stitching your sampler? One way of starting is to find the center of the charted design (usually found by following the intersection of the row and column indicated by arrows in the margins of the chart) and place that center stitch in the center of the fabric. To find the center of the fabric, fold it in half widthwise and lengthwise; the intersection of the folds is the center point.
Once you've found the place to start, place your fabric in the embroidery hoop: Lay the fabric over the small hoop, then place the larger hoop over it (making sure to open the screw enough so that it fits easily over the fabric), then tighten the screw so that the fabric is fairly taut. I've wrapped the bottom hoop with twill tape, which helps prevent the hoop from leaving a mark on the fabric. I almost always use 4" hoops if my piece is larger than a few inches. They fit in my hand well, and that makes me happy and comfortable. I move the hoop around as I stitch. I don't worry that this will distort any previously worked stitches, because it never has. Just don't tighten the screw too tight. Common sense. Some people don't use hoops but I always do. For smaller pieces and minis, use a 3" hoop.
To start stitching, you can either tie a knot in the end of your floss so it won't pull out the front, or leave a few inches of tail hanging out the back side, then weave that end in later by threading it back onto your needle and running the tail end under a few finished stitch (after you've worked several stitches in the fabric). You could also start with the knot on the front side, placed a few stitches away from the center stitch; make your first stitch in the center and work your way over the tail, then cut that knot off the front once the tail is secure. I don't do it that way but it is a way. Pro stitchers will tell you that you should never knot your thread to start and leave it on the back, but I don't know; for beginners I think that whatever is easiest and familiar is best, just to get you going. (A knotless-loop start works well with non-variegated floss, but with variegated I don't use it, since folding a length of thread in half will mix up the variegated color shades and they won't pool properly [see below].)
Now, go. Count stitches on the chart and work them, one by one, on the fabric. Keep the legs of all of your stitches going in the same direction — if the ones on the bottom are going from lower left to upper right, they should always go from lower left to upper right, and the ones on the top should go the opposite (from upper left to lower right). Because the sampler pictured here uses hand-dyed, variegated floss that contains several different colors or shades of color in the same length of thread, I recommend completing each stitch before moving on to the next.
I always do cross stitch this way, anyway, though some people, when they're doing a large area in one color do all of the bottom legs first, then work all of the top legs on their way back to the starting point. I don't like the way the thread pulls on the fabric when stitches are done like this. And with variegated floss especially, working one stitch at a time helps "pool" the shades of color and gives a better effect, I think. So don't do it like this:
Unless you want to. Like I said, no one is watching. Do what you prefer and what will keep you stitching. Keep working stitches in the same color until you've finished all of the stitches of that color in that motif. To end a thread, turn your work over and run the floss under a few stitches on the back, then snip it off. Don't carry threads from one motif or letter to another because they will kind of show through from the front. Finish off each color and each motif.
To start a new motif, you will count the "empty stitches" between the motif you just worked and the starting stitch of the next. I always start the next motif with whatever stitch is closest to the one I just worked — that way I have the least number of empty stitches to count. I walk my needle across each empty stitch space (remember, that's 2 threads), counting in my head. When I get to the starting point of the next stitch in the next motif, I take my needle and gently work the threads away from each other, making the "hole" large enough for me to keep my eye on as I bring the needle around to the back, and come up to the front.
And then I make that first leg of my first stitch on the next motif. And on and on and on through the alphabet!
I am always amazed at how many beginners truly worry about what the back of their stitching looks like. As you improve, you'll find lots of ways to perfect your technique, so if you're just starting out, please don't worry about stuff like this too much. For one thing, once it's in a frame, you will never see the back of it. For another, you are the only person who is going to care what the back looks like. If you don't care, I really don't care. (Even if you do care, I probably still won't care, 'cause I'm like that.) And I can tell you that Andy Paulson did not care for even one little second about what the back of his stitching looked like. And I don't think he has any regrets about that. So, there you go. The back improves as you improve. For what it's worth, here is mine:
Using variegated floss is pretty cool, because it allows you to have several different colors or shades of the same color in one motif, all without changing your floss. You just stitch, and color variations appear. It's a lot more expensive, but very worth it in terms of giving texture, depth, and ease of stitching to a piece. I love it. To keep my floss organized, I buy plastic boxes and bobbins designed specifically for storing floss. I unwind any skeins onto the bobbin (or onto the cardstock label), and label the number and manufacturer on the bobbin with a waterproof pen. After separating strands for use, I rewrap unused strands back onto the bobbin.
If you're working with lengths of floss, as come in kits, instead of skeins, you could also do something like this:
My mother used to work on a lot of embroidery kits when I was a young 'un, and I remember that she always made these: cardboard strips with notches cut into them, labeled with each color name, color number, and the number of lengths included. You can separate the strands and put the remainders back in the notch. I just measured out spaces 1 1/2" apart, cut the notches about 1/2" deep with my old paper scissors, then labeled each notch in the order the floss colors will be used. It's a really nice way to keep the lengths organized, and if your cardboard is heavy enough, it's a pretty sturdy little system. Nothing falls out. We ship comic-book backer boards in all of our kits for you to use this way.
When I'm working a project with lots of different colors, I thread several needles with floss so that they are always ready to pick up and use. I stick them into the side of the sofa and then frequently forget about them, but don't do that. You should stick them into a pincushion. But remember to unthread every single needle in the house when you aren't using them, or put them into a sealed container, like a floss box. Kitties love to suck up thread, and I was at the vet once when a lady had to bring her cat in because he had swallowed a threaded needle. Not good at all. Remember to always unthread everything and put your stuff away if you have kitterses.
Some hand-dyed flosses are not colorfast, and some hand-dyed cross stitch fabrics are not colorfast. I don't wash samplers when I'm done, I have to admit. I don't want to take the chance that they will fade or run. I press it face down into a terry cloth towel with a dry iron, spritzing a bit of water on the back with a spray bottle (test this on a corner to make sure your fabric won't fade). I frame all of my flat pieces myself, with the help of a local do-it-yourself frame shop or ready-made frames. To see how I do it at the frame shop, you can check out this tutorial I wrote.
For a further explanation of stitch counts and various fabrics, this blog post I wrote may be helpful.
These are all just my ways and opinions and by no means a totally comprehensive tutorial, of course. You will find the ways that work best for you as you practice. There are lots of good resources out there, including the best embroidery book ever written in the entire universe.
Good luck and, most of all, have fun!