Train timetables and fares:
http://www.hyperdia.com/
Keisei Skyliner website (serves the Narita Airport):
http://www.keisei.co.jp/keisei/tetud...ei_us/top.html
Narita Express website (also serves more stations than Keisei Skyliner and goes deeper into Tokyo):
http://www.jreast.co.jp/e/nex/
Sanosuke!