Heya!
A Minecraft enthusiast..eh? Your project sounds like fun.
There are some great Photoshop tutorials in the "Tutorials/How-To" folder in the "Mapping Resources" section of the forum. If you get stuck or have questions just ask.. people here are generally very friendly, helpful, and will offer comments and constructive criticism, when asked.
Welcome to the Cartographers' Guild!
-Lailokken