Ok, so there's a couple differences between RAW and file types like tiffs or jpegs. The biggest factor about raw is its more of a file than a picture. You'll have to have a raw editor like Adobe Camera Raw etc... Shooting raw gives you the ability to change those "numbers" that make up that file which in turn projects a picture. It allows you to change exposure, whitebalence, contrast etc... So basically you have shot the picture, but you have the chance to change different aspects of your exposure that you wouldn't be able to accurately change with a jpeg. On the other hand the file size is much larger than a jpeg. If you are just shooting for fun, or to just play around with you don't really need to shoot raw. The highest quality raw will fit what you want just fine. I shoot raw because Adobe Camera Raw lets you change the MP so I can, in a sense, make my camera shoot 25 MP images (it changes the file, which changes the picture like i said before) I hope that makes some sense?
yeah for just screwing around shooting just use a fine jpeg i use RAW when im shooting more serious stuff and you need the right software (lightroom, adobe raw, aperture, etc) to get everything out of raw images