I'm trying to create a texture that has a grungy/dirty look. Do I use a bump map for this? I'm a total novice when it comes to bump maps, so where's a good tutorial, or something, that can help me wrap my head around this concept? Thanks! Karen
Bump maps create the illusion of a 3d texture on the surfaces of your objects. Grunge can come in many forms... if you're looking for "dirty" colors, you can do this with animage map. If you're looking for a distressed surface (think of dents, bumps and scratches, you can use a combination of bump, image and even reflection maps.
Search the tutorials section of this site for the term and you'll probably come up with something.
You might also check out dvgarage.com. They have a lot of information and products relating to surfacing 3d objects.