My experience at the college level varies a great deal between the small colleges versus the bigger schools. There are times when the level is not much better than good high schools teams, but they can also be a lot stronger and faster. Be patient as someone mentioned as they can play through more contact. Be professional and approachable but don't let the coaches get away with more than you usually allow. Make sure they know where is the line in the sand. Better to overdress than underdress when you are uncertain.
Good pre-games are essential when working three-person and dealing with new mechanics and rules. Referee your primary and let your partners (especially if they are more experienced) call their areas and deal with the extra stuff. Soemone feels that you deserve this "game" so have confidence in your ability. One of my problems in the past was that I questioned myself too often during a game. If you make a call or a no-call which is questioned, focus on the next call and don't lose your concentration. You can always discuss the disputed call later with your partners.
Review the NCAA points of emphasis at EOfficials.com. This is a good time to emphasize these points such as palming and post play. Regarding the shot clock, it will become second nature to keep track of it during the game. Unlike the game clock, the shot clock will be above the basket or in another position that is easy peak at during live play or at every whistle. I have included a link to an article I wrote for my association which deals with managing the shot clock.
http://66.49.223.188/english/postplay/august_2006.pdf