JPEG, TIFF and RAW

Newcomers to digital might find this article interesting and informative - I did

http://www.photo.net/learn/raw/

And, before purchasing Photoshop or similar, give Picasa2 a try - it's an excellent freebie

http://picasa.google.com/index.html

That first link is an especially clear and simple explanation of how the camera deals with the data it captures, and of the differences between the various file types.

Good find.

George