I have discovered two things, well three. One is that Blender 3d crashes on my laptop. The main screen comes up, I can insert a figure, then.........oh darn. This happens with version 2.49 and 2.56. Speaking of 2.56, Blender's got a new GUI that's less confusing but just as deep. That's number two and number three is Wings 3D. If you want to figure out how 3D drawing software works, Wings 3D is the short way to go. Wings is a mesh modeler with not too many bells and no whistles.
Now the secret to working any 3D software is getting your brain around how 3D works on a 2D screen. Wings goes a long way in giving you that idea. Not having whistles means that convenient operations are non-existent and it takes planning ahead to get some thing done with minimum headache. But you learn to think and design at the same time, who does that!?
My biggest complaint is that 3d graphics are number crunchy crazy so you need resources like good video chips/card and enough memory. My laptop is ancient and at 512mb of main memory is borderline crippled. My desktop in the remote penthouse of the chateau of upper Linuxville has 1024mb, works the 3d apps just fine. My serious recommendation is to max your system memory for no worries.
So what, you found some manuals, they only tell you about what each function is. You need tutorials. Tutorials give you the play by play via a small project, you know hands on. Even better yet video tutorials because you get play by play instructions, see it then do it. Once you know, you know, you know?
My next project is getting the power of upstairs downstairs. In my present living arrangement, that is awkward. I could use a cart with wheels for my big desktop setup or a new beefier laptop. I like the new laptop idea, maybe a tablet.