The sites that come to mind would be ones like here, Rendo, Blender forums, Deviantart, Valve’s Steam gaming forums, etc. If it’s a game, since it’s non-commercial, it would be classified as an indie game, so you may find some resources at Desura or ModDB. Also, it may be something you have to start a Kickstarter for so you can fund the project.
It really depends what you’re trying to do. For example, I probably wouldn’t post on gaming forums if you’re not looking to make a game, or you’re making a non-gaming related animation. People who get into it kind of already know the world and where possible resources would be.