First go to Tokyo Station (by limousine bus or JR Narita Express train; about 80 min). To get to Nagoya Station from there, take a Nozomi train on the JR Tokaido Shinkansen Line (about 105 min), or an express bus (around 6 hours; there are 8 or 9 buses a day).
Narita International Airport (English):
http://www.narita-airport.or.jp/airport_e/index.html
Express bus information (English):
http://www.jrbuskanto.co.jp/mn/ceindex.cfm
East Japan Railway Company (Chinese, English and Korean):
http://www.jreast.co.jp/e/index.html