Lindsay, I presume you are utilizing things like Facebook to attract people to your programs. For Social Networking Sites one question you should ask is who is going to be the "interface person" or persons from your organization. who is going to manage the profile. Will it be from an individual's profile or the organization? If an organization, what links might there be from your staff (or former staff) to your organization? The big question of course is how all these people related to your organization represent themselves online and how they might represent you. It's a difficult thing to manage.
As far as communication with minors, there are several ways to approach it. The big issue to consider is could there be inappropriate conversations under your organization's name? This is in many ways a risk management issue, just like running a safe ropes course. You have to balance the benefits of doing it with the potential risks involved which could be danger to a child or to the reputation of your organization.
Email - you could only allow staff to be in official contact if they are using an official organizational email address (John@campminihaha.org). This at least allows your mail server to track messages. If a staff person is using a personal account like GMail or Hotmail all sorts of things could be happening that you have no access to. Also, there are software programs that will allow email monitoring if you feel that is needed. Another option is a listserv where you can have moderators controlling what messages actually go out.
There are numerous Web Discussion Forums either as hosted services or part of certain sites. Here's another place where you can set up Moderators who have to approve messages before they are posted and can be set to do the same with replies.
I hope that gives you some things to consider.
Rick Curtis