I was reading a recent post in the critique section where a number of responses included modified versions of the original photo..crops, colour adjustments, and so on.
Personally, I would not want any of these corrections done to a photograph that I post for critique. If I want an image in black and white (or cropped or sharpened or whatever), I will post it that way. If there is some suggested image manipulation I don't know how to perform, I wouldn't mind a link and some information on how to perform it, but IMHO that's as far as it should go.
I think (to start) there are a few rules that would help the critique form. One is that the original photo should stay posted and unmodified so that everyone is discussing the same image. Second is that only the original poster should be able to post modified versions of the original photo to the thread based on suggestions of other posters, or what have you.
Also, there are wonderful critique guidelines at Dyxum
here that should would make a good sticky to read before posting to the critique forum, IMHO.
Thanks, I look forward to participating in the forum!