In Addition to the Diffuse map which is the color map, there are other types of texture maps that help bring your 3D model to life.
Lets take a look at generating a Ambient Occlusion Map. An AO map, sometimes called a dirt map, creates shadows on your model that you can then use in conjunction with your diffuse map to achieve greater realism. AO renders are also nice presentation renders if you don't yet have a diffuse map applied.
In the tutorial below well take a look at creating AO map render.
AO map render from Trance Lion on Vimeo.
The next video talks about generating normal maps. A normal map cheats high frequency detail on a low poly object. Since games require real time rendering, poly counts can't be to high other wise it would slow down game play. Normal maps help create fantastic detail without adding in any additional Polygon. The video below talk about the basics of creating a normal map and the principles behind it.
Normal mapping blog from Trance Lion on Vimeo.