I'm a graphic designer by trade, so I have tried a ton of various websites for graphics, web templates, etc. A great one is Mighty Deals (www.mightydeals.com). They offer a lot of free graphics, photos, and fonts that you can download and use on your site (http://www.mightydeals.com/free_stuff). They also sell items usually at a reasonable price. I bought a royalty free stock image collection from them years ago that contained thousands of images for only $75. They also offer Wordpress themes at a very affordable price.

Definitely check them out if you need quality graphics for your site. Their offerings change all the time.