I am exploring a way to gather models, sprites, and tools to build more of these kinds of assets. Exotic Sounds like missile launches, spaceships and so forth seem to be a big problem for some people, although there seems to be plenty of sound files around for me. Music that is game like in nature also can be difficult to find, at least music you can reuse for no cost. And then there is Foley sounds, like doors, windows, walking, etc. these can be difficult to find, but pretty easy to make.
Expression Suite is one of the best tools around!
Expression Suite contains:
3D tools that are free to everyone:
Softimage (now owned by AutoDesk), can only be used for non-commercial use, similar to the EULA for MSDNAA.
Use for whatever reason you want:
TrueSpace 7.6, and this can be used for whatever reason you want to, the software is free and the company has been closed down!
Blender, this product has a great community and is difficult to figure out how to use, also, it charges for tutorials
So dig into some of this great software, especially since it is no cost if you are using it for non-commercial use and a student (except for Blender and TrueSpace 7.6)
I think they already closed down the site.