first tutorial in a 2 part series on creating textures for games. takes the reader step-by-step through the process of gathering their own stock photography, through creating tiling diffuse, specular and normal maps. this tutorial uses photoshop, but the logic behind it should scale to all 2d graphics apps. learning to texture? this is a good place to start. when done with this tutorial, look for part 2 here on turbosquid.