The following picture is what I created. We will now be saving two different pictures from what we created, an image map and a bump map. Now turn off the border color, the letter, and the woodcolor layer and save a copy as Abump.tif. Your two pictures should look like the one above and the one below. Save As, so you can edit it later.
All faces are now individually selectable.
Choose the move tool and click on one of the sides of the cube. Click the square above Map and load the letterA.tif that you created and choose ok. Then click the square next to the Bump field and load Abump.tif and set the bump to the desired level. I used about 7 for mine, but you may wish to go higher or lower. You can edit your Photoshop layers and just change the color of the border and make a different layer to apply to other sides of your blocks.