If I were to make a fan site of lets say The Simpsons, is it possible to use images of the characters on my site? I notice some sites have something like this on them. Does that make it legal to use or is it just something people think makes it okay?
Technically speaking any image related to the Simpsons would be copyrighted, although they aren't always strictly enforced against, especially sites dedicated to promoting the programs. Legally, I would send an e-mail informing them of the fact that you want to start a fan site, and give a short description of what you plan. If you intend to create your own images, send them some samples to indicate the type of images you will have on your site. Copying pics from other websites will eventually land you in trouble.