Does anyone know of any cool 3D modeling problems that are available for download online (like Sketchup, Autodesk, etc)? If so I would greatly appreciate it.

Thanks.

Sure.

For beginners I highly recommend Google Sketchup. It has everything you need and is probably the easiest program you can use. The link to Google Sketchup is here. http://sketchup.google.com/

Autodesk 3D Studio Max is a very good program, in my opinion. A lot harder to use than Sketchup and may seem impossible to use for some people, but once you get the hang of it, you should be right. The link is here. http://usa.autodesk.com/adsk/servlet/index?id=5659302&siteID=123112 3D Studio Max Trial is available for download, the trial lasts 30 days which is is a fair amount for a trial.

I suggest that you get started on Google Sketchup. But when you feel you have mastered it, and you would like to go advanced, you should definitely try 3D Studio Max. Also a great plugin for 3D Studio Max is Vray, which enhances the quality and realism in your renders. The Vray link is here. http://www.vray.info/

Well I hope I helped, and good luck! :)