You could also try SketchUp 6, from Google. Simple but great for quickly putting something together. I've found this particularly helpful when doing architectural/furniture work.
There's Maya Personal Learning Edition.
It's for non-commercial use and is based on 8.5. I think it's the same apart being limited to a single core and all models have a watermark.
DAZ released Bryce 5.5 as a free download when 6.0 came out. It's not as powerful as some of the others but it's pretty easy to use. Available for OS X and Windows at Download.com
Maybe you can give Wings3D a try?
Its so easy its scary, so ofc its 3D for the ultimate beginner 😛
There should be some links on the site for some tutorials you can follow 🙂
You could also try SketchUp 6, from Google. Simple but great for quickly putting something together. I've found this particularly helpful when doing architectural/furniture work.
Maya Personal Learning Edition would be the best except it water marks your renders so is not really an option unless you are using it to test if you want to buy the full version of Maya which is slightly more expensive 😛.