Copyrights and the Internet

[Vulgivagus hagiographus]

I'm not sure if this exactly where this should go but I can't really think of any place else it would fit. My question is on how copyrights work over the Internet, specifically in the area of what's known as fanfiction (stories written by a fan based off of a published work) and/or fan sites. www.fanfiction.net is probably the largest site for fanfiction. I was just curious on if this is actually completely legal. Say I'm a crazy Lord of the Rings fan. Is there any copyright law against me making a website based off of the Trilogy, write stories and/or draw pictures off of the books, so on so forth? Can I do all that if I just say, "Lord of the Rings belongs to Tolkien. I'm just a crazy fan showing my devotion and not making any profit off of this"? Can I make sites like this if I follow certain guidelines, and what might those guidelines be?

I figured that if anyone knew about laws and such that they would be in the politics forum. I would greatly appreciate any information on this! Thanks!