You should check out john sayer's site for studio floor plans and design info.
http://www.johnlsayers.com/phpBB2/index.php
Great guy, great site moderators... really helped me out on my own home studio design project.
Also... Download a copy of google's free SketchUp to do easy 3D models of your studio layouts. A whole lot easier than doodling on paper (especially if your handwritting is shizen like mine).