The cmc-leaders list may carry trip announcements and reports, meeting notices, newsletters, etc. There is no charge to subscribe, but you should be a CMC leader or leader prospect to participate. All messages are archived, and are considered public domain. They may be included in various newsletters or forwarded to other lists.
Org lists are for gear discussions, political debates, etc.
Keep in mind that any message you try to send out to the group should come back to you within a few hours to a day. You should get 2 messages when you subscribe. One is this file, the other is climber.org-rules.txt, and both of them contain stuff you'll want to know later. Even if you don't think so now. To unsubscribe yourself from ALL lists at Climber.