Hmm. When I've been in the casinos, I've seen them hit one button in the cabinet to get to the menu, and then combinations of that same button as well as the deal/draw button to move through the menus, as well as the keyswitch to activate certain things (if memory serves).
You could try contacting IGT (igt.com) to see if they have a manual either on their site or available for sale -- I'd make it clear that you recently purchased the machine and perhaps even give them the model and/or serial number of it.
Another option would be to try and hit up a slot tech at your local casino for information. So long as they don't think you're trying to get information to cheat them, you might just find out everything you need from someone who works on the machines on a daily basis.