I hate to buck the system here, but I shoot almost exclusivly JPEG, topside and underwater. Well, I have up to now, my next trip I may do some Uncompressed shooting to try and step my work up a notch.
My camera is set to the highest resolution i can get without going to the "uncompressed" mode. My camera makes TIF files that I have to convert with the software that came with the camera before I can manipulate them in Photoshop. Basically just open it with the software and save it, then it can be manipulated.
Shooting JPEG is just the way I was taught to do it, I was told mostly because of write time to the camera. My instructor is a professional photographer and she says she doesn't shoot RAW. It will take your camera a lot longer to write an uncompressed file than it will a JPEG and you may miss that second shot because of it.
I do agree that shooting RAW is the best format for file manipulation, there is soooo much more information there, but if you are new to Photoshop also, that info may not be any good to you anyway.
You may want to shoot JPEG's until you really get to know your camera and develop you photography skills. That way you can shoot more pics and more often to improve your skill with your eye and camera. Then move to RAW once you feel you have a good grip on the process.
Another thing to consider is file size, the difference for me is JPEG: 1.2-1.4 Megs; Uncompressed: 14+Megs, some folks either don't want to deal with that big a file or the file slows down their computer quite a bit. Plus there's the issue of storage, 14+M files eat up storage quick.
Just some fuel to the fire, best of luck!