Once you get into intermediate knitting skills like stranded knitting, intarsia and lace, you'll probably find yourself wanting to knit a pattern that uses a chart to communicate some of its information.
A lot of knitters are afraid of charts, but they're really a great tool because they allow the designer to communicate a lot of information that it would take a lot longer to do in words. They are a way of showing you rather than telling you what your knitting should look like, and they're a great method of insurance against mistakes because you can compare the chart to your knitting and see if you've made a mistake.
Reading charts, whether for stranded knitting, intarsia or lace, is not really all that difficult. What you need to remember is that you read the chart in the same way you knit your project which, in a lot of cases, means from bottom to top. Because knitting charts show the right or front side of the knitting, you have to read the chart from right to left on right side rows and from left to right on wrong side rows. But if you're knitting in the round you can read each row of the chart from right to left.
Another matter of importance is how you keep track of where you are on the chart. For simple intarsia designs you'll probably be able to tell just by looking where you are in the pattern, but for more complex stranded knitting, cables and lace it will help to use some kind of marking system to indicate which row you are on (or which row you last worked if you're picking up your knitting after a break). There are lots of different methods, from tick marks to row counters, magnets to sticky notes, and you will find the way that works best for you through experimentation.
If you have a favored way to keep track of where you are on a knitting chart, I'd love to hear it!