Hello all...My first post...please help

Hello, This site is great. Thanks to all of you that spread the knowledge for others to consume. I'm building a project studio in my garage. There is an image included with this post. The floors are concrete but I plan on putting down carpet (if that's the best idea). I have to put in insulation and sheetrock as well. I have no clue about how to layout my studio correctly for sound. Any suggestions will be greatly appreciated. Currently I use Pro Tools LE with the mBox and I'm a DJ / Producer that makes soul / funk / hip hop / acid jazz cuts. I plan on recording instruments, but very rarely at the same time. I play most things myself. I would like to put a mic / iso booth in the room as well because I will be recording vocals and would like to reduce background noise as much as possible. I hate to sound totally unprepared but I don't understand where to put foam or anything else so the more information the better for me because I like to understand so I don't have to keep bugging people :) Thanks all. By the way, I forgot to put it on the diagram, but the ceiling is 7'10".