Get you some cheapie OPK, that is the best way! Also I liked the little ovulation tracker on this site. You can also start charting temps, it is a good reference tool to figure out your cycles. It does not "predict" ovulation but you can tell by an increase in your temp that you did actually ovulate. it will help you start pinning down your ovulation window, or time frame.
read the book... "Taking charge of your fertility"... it is fantastic and really opens your eyes as far as ttc (or not for that matter).
Depending on your cycle length you may not ovulate midcycle. If you have really short cycles you could even ovulate during your period. If you have long cycles you will ovulate late in your cycle.
You cannot base your ovulation on your last period. It just won't work unless you have perfect 28-day cycles every single month. The rule is that you will get your period about 14 days AFTER ovulation.
So if you're regular, subtract 14 from your cycle days and you will ovulate on or around that cycle day.
I used the CM method. There are some great health pages you could look at. Go to the top of the page and click on health pages (right-hand side, under the word DISCUSSION).