Number2.com
Producer of the "GRE Companion" test tutorial also has a nice directory of school homepages and references for going to graduate school
TOEFL (Test of English as a Foreign Language) Site
If you are an international student planning to apply to a college or university in North America, you may be asked to demonstrate your English proficiency level by taking the Test of English as a Foreign Language, as well as the Test of Written English. If you are seeking licensure or certification in a professional or occupational field, or anyone applying for a teaching or research assistantship, you may also be required to submit scores from the Test of Spoken English. This site should answer all your questions.