How do I add a texture to a cube with different faces?

Here is the greatest example… How would I create dice? I need each face of the cube to look different. Would I just create a picture in Microsoft Paint with the design of a cross, containing 6 squares of my different colors/designs, or is there a better way to do it?

Here are the basics… I am creating “cube characters”. The front of my cube should contain a face, the back and sides of the cube should match the “clothing” component, and the top should be a specific color or design as well. If the player decides that he or she wants to change the facial appearance or the clothing, how would I go about implementing this in the game?

Thank you in advance for any HELPFUL answers.

As @rutter commented/answered, you should follow one of any of the UV/texturing tuts