Darn AF!!! I'm so sorry... I'm glad that you're charting, though. You'll get a look at how your body is working every month.
Generally, a spike of .4 degrees or so (Fahrenheit) means that you've O'd. I'm occasionally a slow climber after O, so it may take several days to see that my body temp has risen and indicates ovulation. When you're looking at most charts, though, the day of the big spike is the day *after* O. Make sense? Say that today, your temp is 97.4 and you O today. Tomorrow, your temp should start going up.
I have no idea if that even helps...
FF also has some great explanations of how to read their charts--what indicates ovulation, possible implantation, possible pregnancy, anovulatory cycles, AF, and more. It might be worth a quick glimpse!
Again, sorry about AF, but I hope that this charting thing turns out VERY well for you!!!