To add different textures to each face of a block:

1. Select the block
2. Right click with the block selected and choose "Properties" from the menu
3. Select the "surface" tab
4. Use the arrows on this panel to "select" the individual face
5. Make sure the "texture" button on the panel is selected
6. Apply a texture to the face by double clicking the texture from your .wad in the texture panel.
7. You should now see the thumbnail in the surface panel display the surface you selected


When you create a hollow block you will see that it is created in a
"group" folder. To access each of the blocks within that group:

1. Select the group
2. Then "scope down" with the scope down button on the toolbar
or by selecting in the toobar menu Object->Scope->Scope Down,
or use the keyboard shortcut CTRL+Page Down
3. Then you can access each of the blocks independently and apply the
textures using the steps listed above.
4. When you are done, just scope up.

If you want to break the group up permenantly, select Object->Group->Ungroup
or ALT+G.