Do you have insulated garage doors? Is the seal around the garage doors (including access door) tight? Is the bottom seal on the garage door working? Look at these areas first!

You may want to look at putting insulation in the ceiling of the garage. A lot of garages have insulation only in the walls. Do you have access to the ceiling without cutting a hole in it?

A product called reflectix helps you DIY your garage door insulation your self. See website for more infomation

http://www.reflectixinc.com/

insulation above the bed room will provide the most bang for you buck...is it accessible?

Why is the best less dirty kind of insulation? I know in NC we need r-38 and I want the easiest to you. Which way would the paper go?

Access to the space often dictates what material is used...in open "bays" roll are often used because the access is there. Once the room is finished this may not be an option...here upgrades are often done with blown insulation. You should start with getting a energy audit / insulation inspection performed this will pin point where you need to focus your efforts.