#4
AutoCAD is used for drafting. It's not free but it shouldn't be hard to find if you don't mind illegal downloading.
#5
Just look for AutoCAD on bittorrent. Although it would be a lot better to just buy the program. A lot of professional architects use it for their work. I'm using it for 3d and interior design. Really a cool program, but you need to have algebric knowledge to use it.
#7
Google Sketch-Up is the one to go with.

But you need a good computer so that it wouldn't lag like hell when you use it.
Quote by RoamingConflict
This one dream involved me, one random girl, midgets and a pie.


...and midgets ended up f*cking her. I got the pie.