Theres the APA, ACA and NSWA websites but you do need memberships to use them. There isn't much on any of these sites that is very revealing, although there is useful information from a professional development angle.

For writings by and for MH professionals, the Carlat Report and Psychiatric Times are informative, although are psychiatric and research oriented. As far as forums, myshrinkwrap.com is an interesting read and sheds some light on things from a Ts perspective.