Webyoung.com -- Awesome exclusive and original teen content.
GiveMeTeens.com -- Great teen niche site from Devil's Film
MyTeenOasis.com -- A teen site from Silverstone DVD, a lot of popular pornstars first time on camera can be found on this site.
Plus some not exclusively teen sites but they have a LOT of teen content:
RoccoSiffredi.com -- the Italian Stallion, legendary performer and teen lover.
OutoftheFamily.com -- Lots of Stepdad + Daughter and Mothers teaching daughters content.
PeterNorth.com -- The Cumshot King, lots of teens and popular pornstars first time on camera vids here.