I just signed up, but I get a "no permission" error when I try to post
When you register for the forum, the forum software will send a confirmation email to the email address you provided. The email contains a link you must click which will activate your forum account. You will not be able to post until you do so. The email is sent instantly when you register. If you don't see it in your email inbox, check your bulk filter in case your ISP thought it was spam.