I was going to mention that same thing. There are a LOT of guys out there who will try to claim you if they find out that you're new to submission... some are horny net geeks who just want to get off on telling someone what to do... some are a bit more dangerous.
Go slow.
Thank you for the advice! I would imagine it's difficult to distinguish sincere dominants from the false ones, however, unless it's completely blatant.