I took a digital photography course during the summer a couple years ago. If you're curious, what I found most helpful was really just the explanation of how to use my camera's manual controls and what each control meant - it's amazing what a difference it makes!
Once you've figured out how to get everything focused how you want it and such, it's all down to figuring out how you want to position your work, if you want props, etc.
For examples of way better photography than mine:
[link] Well - way better everything, really, her work is fantastic. But her photography is excellent: note the angle and focus she uses, what kind of backgrounds, whether she groups items or photographs them alone... Her shop has more examples of her photography, too:
[link] I'm a bit jealous.