Well, if you've never used any CAD software before, it will probably be confusing when you first use it. I would say after 5-10 hours of messing with it, you will be able to produce something useful. I really probably don't use all the functions like a REAL drafter might, to be super efficient. If you want to do 3D, you'll need to get a handle on the difference between the "view coordinate system" and your "drawing coordinate system" It's a weird idea but makes sense after a while. Other than that, all I do is make basic shapes, like boxes, circles, triangles, then I extrude them to become solid parts. If you end up going with Autocad I'd be glad to PM you with a little more how-to to get you started. There are also some tutorials in the help menu I think.
enjoy
wm