Just a follow up to this note. I've added notifications to the initial sign up messages shown immediately after sign up, even before email verification has occurred. A second notification is sent to users after their account is verified. I setup and tested a dummy account this morning to confirm.
When going through the process I see there already is a notification about not posting URLs, but I have made it more apparent now.
I'm working on some automated notification popups too, but it's a littler over my skillset, but hopefully can get it figured out.
There isn't a rules page, but I am crafting a "Do not post links as a new user // how our spam detection works" thread, and will post it shortly.
JW