My friend Mindi has an amazing post on her experience leading a small group of Middle School girls through their entire time in MS. For the whole article, click on the link above. Here's a short clip...
Introduce yourself. send a letter, email, or make a phone call to get started. make a point to meet them in person.
Make yourself available. be sure they have your phone number and email. let them know you're available as a support and resource for them and their student.
Help them connect to the larger ministry--make sure they're in the loop on total group events, upcoming outings, etc. (I can occasionally be absent-minded about this)