Does anyone know any good educational websites ? I'm tired of going on everyday and just checking my myspace. ?

I saw on a comcast on demand special on how much kids use the internet, that one school had all there students using this website that gave them notes and book reviews, I just can't remeber the site. Also I think I didn't do the best I could on the PSAT's verbs so anything that will better my vocab is a plus. (: thank you in advance.