• If you make an account yourself, you get the "Basic" role. That basically lets you do everything except create new posts.
• If you have the "Trusted" role, that means you're trusted to create new posts without turning this place into a steaming pile of spam.
• If you want the "Trusted" role, just ask.
• If you invite someone, they'll automatically get the same role as you.

I feel like I should make a FAQ section with this kind of info, but this'll do for now.