[whistleone]

As someone that's experienced the intramural sports world on all sides (participant, official, supervisor, trainer of officials), hopefully I can help. I would imagine that your officials are receiving some sort of pre-season training. If not, this is obviously your first step. A good training program should include adequate rules study (the Basketball Rules Fundamentals is a good place to start), classroom and on court instruction, followed by scrimmage games.
During the first few weeks, constructive feedback is essential. Timeouts, halftime and post-game are ideal times to provide feedback. Being their supervisor, it will be natural for them to look to you during the game for answers. It's my opinion that unless there is an obvious rule misinterpretation that affects the outcome of the game, you should not step in. Part of learning to officiate is dealing with missed calls and the results of those calls. Obviously, if your official's or a participant's safety or well-being is at risk then you must take action.
Throughout the season, I send emails to my officials with encouragement, clarifications on situations that have come up as well as case plays (many of which come from this board).
Be prepared to have officials that just don't get it or just don't care. These officials will probably be the ones that end up not getting very many games. Find those officials that have the desire to get better and make sure they do that. I think we'll all agree that the only way to get better is to call more games.
If you want/need training materials or evaluation tools, feel free to email me.