Beth,
First thing(very important)! Stop using your computer all together. The more you use it, the less chance of recovering any files. Best thing to do is to find a friend with a mac and download a trial version of
File Salvage onto your friend's computer. Then boot your Mac into Firewire Target Disc mode by holding down the
T key. Then connect it to your friend's mac with a firewire cable and run File Salvage(from your friend's computer) and have it scan your computer(which will show up on the other computer as an external drive). File Salvage should give you a detailed report of what files can be recovered. If it finds the files that you deleted, you will then have to pony up the 90 dollars to get the full version. Only the full version can recover the files.
You also might want to try
Data Rescue II from Prosoft.
Good luck, and please think about a comprehensive backup solution.
Grant
1.5GHz PB, 15gig 3G iPod, 40gig 4G iPod, Airport Express Mac OS X (10.4.3)