The idea of a minimum post requirement is appauling.
Firstly because, IF!! we add a minimum post before people can make a link THEN!! the fools making the effort to spam will just spam until they reach the minimum post requirement, resulting in more spam.
And secondly, you're assumming people joining are "noobs" and have nothing relevant to say. By this i mean, if somebody was asking for help and there was an unregistered person who knew how to help, and they decided they'd give them a link or something along those lines. Then guess what..........