HOW SHOULD I GO ABOUT IT?

ok...heres the thing...its cold...i need to work on my trucks, but i have nowhere to do it and i am impatient to wait for spring...so i was seriously thinking about building a garage in my back yard (prolly about a 2 car)...what would be the best way of going about this?...i dont need anything real fancy, maybe like a poll barn type deal with two garage doors, but pretty good size so i can work on stuff...my brother knows how to build them and my dad knows electric and can wire it up...should i jus buy the materials and build it myself with the assistance of my dad and bro, or pay someone to do it?...if i decide to build myself, does anyone know of a website that i can go to with different types and maybe a materials list for a do it yourself type job?