http://www.pokertracker.com/ , you can download a trial for free, its either 1 month or 2 months long, forgot which.

also people use something called poker office i believe, which is a bit cheaper.

free programs that you might find helpful include pokerstove and pokergrapher. The latter i think requiers poker tracker...but im not sure. Pokerstove will show u how one hand might rank against a range of different hands.