on calls, write out a check list of interview questions to cover with all candidates, go over profiles of good candidates and explain what makes them good....and do the same with bad candidates. I agree with Dean too, don't put them on the internet or let them handle any advertising response. Teach them how to source, how to break down companies and then how to call and recruit those people. Have them focus on reactivating old candidates, call them, and call their references and ask everyone for referrals. Teach them how to use the internet to research company information and make call lists.
That's what I've seen work. If you teach them too early about job boards, that's all they'll do and won't add nearly as much value as they would if you really teach them how to recruit.
Peter Leftkowitz has great training videos on this you might want to have them review or even attend.