If it is an answer to a specific question then it would be all right. If you just started a thread that said: "Read Cool Cruiser Magazine" then that would not be allowed.
It is the same as someone referring a cruiser to Priceline or Hotwire when they ask about hotels or insuremytrip.com when asking where to find travel insurance. That is fine but starting a thread that said: "Use Priceline for Your Hotel Booking" would be a violation and removed.
It is great to share information resources with everyone and we know that our regular readers are not trying to sell something but if we let our long time readers break the rules then we can't tell a new user, who just wants to promote their website, that they can't do it.
Take care,
Mike