What type of stuff is allowed to be sold here, and what is not, if anyone can fill me in, I would appreciate it.
You're going to get an infraction for that(guess), because you can find the answer in the FAQs/Rules, and the infraction is going to say something about post count
You can sell Links, Websites, services (designing, programming, directory submission services etc.) and Link exchange in B/S/T forum. And i don't see why he would get an infraction for asking this.
Or wrong forum but I'll be generous don't sell warez, porn etc but you can sell your adult domain, or adult site. If you are promoting an affiliate scheme it should be yours, and not via an affiliate link (ie MLM). Use common sense, this is a webmasters and internet marketing site - you should be selling related goods and services.
Not using the search could piss a moderator off http://forums.digitalpoint.com/showthread.php?t=116836 Just read the Rules & FAQ and familiarize yourself in those forums you intend to post in. Hardly anything will get you banned directly.