I had the pleasure of visiting Japan a few years back and when I was there I managed to talk my wife into riding a subway for an hour to attend a J-League match between Nagoya Grampus Eight and FC Tokyo in Nagoya.
Once we finally figured out where the stadium was and deciphered the Japanese only tickets to find our seats, we settled in to enjoy the game. The match had a fantastic atmosphere and entertaining style of play and I've done my best to follow the league ever since then. (Nagoya won 1-0 in case you were wondering)
The 2008 J-League season just started a couple of weeks ago and I thought I'd list a few of the sites I use to keep track of the league here:
Gambare! J-League Highlights Fridays at 5:30 p.m. EST on Fox Soccer Channel
The Rising Sun News
Official English Language J-League Site
Official Weekly Schedule and Scores
Official League Table
Official J-League Club Profiles
The Japan Times
Bigsoccer Japan Forums
I occasionally catch a live streaming game from myp2p, but they usually start between midnight and 4 AM Eastern Time.
2008 J-League Previews
2008 J-League Kits
A post from football-chat.com that shows the 2008 uniforms.