I charted for over 5yrs after reading Taking Charge of Your Fertility (for $3 at used book store). I thought I'd be overwhelmed, but was a pro and know waaaaayyy too much about my body :)
For me, those ovulation kits didn't work (tried the stick and the fern). It was easiest and most accurate for me to go by my signs (cervical opening, cervical fluid, etc). I learned that most often, I ovulated on day 8 or 9 (very early compared to most women I know). Ironically, the 3x I got pregnant while charting, however, I ovulated after day 21!
For my friends who had no desire to chart or learn about their bodies, it was easiest for them to just have sex every other day, starting with the day their period ends, ending at 2wks.
Good luck!!!!!