Cathy,
DO NOT BUY A SOFTWARE PACKAGE !!

By all means pool your money, but put it towards developing your own techniques.

I have used Dr Huangs Race Predictor program and though it seems very atractive at first, over the long term you will only break even with it (if your lucky..)
Some people have reported success using it on the first couple of races of the day only, not sure about the logic behind that..?

There are many similar packages for sale and a lot of very expensive systems too.
Dont touch them.
If you have a spare couple of days, have read some of the postings at: http://www.zip.com.au/~keeva/grq/forum/

Dude.