NJ Randonneurs also has some rides; see their website:
http://www.njrando.com/
The Forrestal Village start point is about five miles from the Princeton Junction train station. The Cranbury start point is about six miles from the station.
I was going to mention this as well. I just actually signed up for the 120k ride with them since its probably one of the earliest rides of any significant miles I will do this season.