Go find the book Taking Charge of Your Fertility. It's a great read, and explains how to chart. A lot of women also like the fertility friend webiste for charting. The site used to be free, but since I haven't used it since over a year ago I'm not sure anymore.
TCOYF is a great book! The fertility friends website is not free anymore. However, ovusoft.com is free and there are lots of ladies there more than willing to help (although most of them will first direct you to the TCOYF book). Most of the women on ovusoft.com use software to chart, but I find paper charting just as beneficial (and cheaper!).