You will need to UV unwrap. There are lots of tutorials for basic uv unwrapping floating around on the web. But the easiest way for someone new would be...
1. select the cube
2. go to create uv's and select automatic method
3. with the cube selected open the uv editor and you should see all 6 sides individually mapped
4. go to polygon/uv snapshot, pick a texture resolution, and create a file
5. you can now bring that file into photoshop and place images on any of the individual sides. put them in a seperate layer from the uv snapshot.
6. turn off the uv snapshot layer and save the texture image
7. go back into maya and create a new material.
8. click the checker box to the right of the color, select file and browse to the texture image
9. apply the material to the cube and press the 6 key on your keyboard to see the texture images
I would recommend looking in the tutorial section here for more detailed tutorial. Also you can search on texturing a die or dice as this will be very similar to what you want to do.
I hope this gets you going in the right direction.
Note: The result of the automatic unwrap may have the sides rotated 90 degrees in random directions. To see what faces in the uv editor belong to what faces on the mesh just select a face on the mesh and the corresponding face on the uv map will highlight. To determine orientation pick an edge on the face. You can rotate the shells in the uv editor to get them all in the upright orientation for easier painting in photoshop.
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675
Last edited by ctbram; 03-10-2011 at 02:55 PM.