I'm a very visual knitter, and I love charts. As a matter of fact, unless it's very simple, I can't follow instructions for cables or lace without a chart. I need to be able to see the design in black and white, and then I can knit it easily.
But I realize this isn't the case for everyone. Some of my friends work better from instructions, and aren't sure how to make heads or tails of charts. So I thought I'd do a little tutorial, for any of my readers who would like to work from charts, but don't know how.
First of all, knitting charts are read from right to left, and from bottom to top, because that's how we knit. I'm using the chart from my most popular pattern "Laura" as an example. You'll notice the row numbers on the right side of the chart, and that they are only odd numbers. The reason for this is that the even numbered rows are the wrong-side rows, and they are meant to be simply purled across(which is stated in the pattern). Each box in the chart is one stitch. The key is important, so that you understand which symbols mean which kind of stitches.
So, looking at Row 1, which is the bottom row, reading from right to left, there are four empty boxes, which are knit stitches. Then you see an o, which is a yarnover, then a left-leaning \, which is a slip,slip,knit decrease. Then there are four more knit stitches, before you come to the bold vertical line. The vertical line denotes the pattern repeat. So you will repeat what is between those bold vertical lines for as many times as the pattern tells you to. Okay then, inside those bold verticals, still on Row 1, you have two knit stitches, a yarnover, a slip,slip,knit and four more knit stitches. This sequence would be repeated until you come to the last seven stitches. Then you would finish out the rest of Row 1, with two knits, a yarnover and ssk, and three more knits. With the first row completed, you would purl row two, before going on to the next row in the chart. You just work one row at a time, using whatever method you like to keep track of which row you're on. Just a quick look at Row 3, still reading from right to left: knit 2, k2tog, yarnover, knit 1, yarnover, ssk, knit three..then the repeating part: k2tog, yo, k1, yo, ssk, k3...then the last bit when you're down to the last seven stitches: k2tog, yo, k1, yo, ssk, k2. Row 4 would be purled, then on to Row 5...
Now, when you come to Row 7, you'll see that those bold vertical lines shift to the left by one stitch. The reason is that it's easier to read the lace motifs, if they aren't split. If the line went straight up, it would split the yarnover and ssk in row 9. It wouldn't have any effect on your knitted piece; it's just for readability's sake. Really all you need to remember is that what's between those bold lines is what you repeat.
I hope this makes sense; if anything is unclear, please leave a comment, and I'll do my best to clarify. For the whole pattern for "Laura", go here: http://christineolsonoriginals.blogspot.com/2009/07/my-first-pattern-laura.html