Cheap Graphics:
I bought this sprite pack today and it is well worth the $16. It has some really good graphics in it and a variety of styles.
Sprite Works is an extremely affordable sprite pack ($20) and it has a wide variety of graphics in it. They are extremely good quality.
Texture Works is ideal for creating tiles for your 2D games. It is only $14.95
Free Graphics:
I am sure everybody is familiar with Reiner's work, but it is worth mentioning for those who aren't. Very wide selection of free graphics and everything is "renders" of 3D models. A huge variety of animated sprites, tile sets, vehicles, etc.
RTiles has some 2D graphics perfect for a dungeon crawler. A huge assortment if you download all of them. Even some "3D" looking graphics
This one is "connected" to the previous link, but a while back, it contained a few different graphics, that the previous link didn't have.
Lots of 2D graphics can be found here. A wide variety of styles and quality.
Gaming World literally has a lifetime supply of 2D graphics.
Although this book, Designing Arcade Computer Game Graphics is dated, you can download it for free and it is useful and the techniques can easily be applied to Windows image creation/editing.
Hopefully somebody can benefit from this post
