Where can I find graphics that i can use on my web page?

I'm getting into the who webpage design thing, but I'm much more a programmer then designer, so when it comes to graphics and generic photos I'm hoping to find a source of graphics and photos (even if I need to pay) that I can legally use on my sites.

I'll probably combine and tweak them some, but for someone who lacks in the artistic area, a starting point is very helpful.

Any suggestions of the best website or product for this purpose?