Try to act like an adult. Off-color language is fine, as is the occasional dirty joke. Weird behavior is tolerated, plain and simple jerks aren't. Don't send attachments to the list. When in doubt, do what Nettiquette advises.
Good manners go a long way towards friendly conversation.
Don't worry about tons of regs, just have a good time. If you need help, don't be afraid to ask. Please only contact her if absolutly necessary. Mel is very busy these days, and can only respond to your requests so fast.