Once upon a time the appropriate resource was Doctype, but I've not seen it mentioned in recent months. I'd suggest that you ask questions related to the mechanisms of your design (JS/HTML/CSS...) on Stackoverflow itself, since that site attracts many html designers and devs (even if, strictly speaking, web-design might be off-topic),and questions related to the user interface itself, and design, on User Experience.
With regards to the edit:
Specifically I wanted to ask questions about the business of Web Designers. Stuff like "What are things to look for in a designer's portfolio when looking to hire?", "What are the best resources for hiring the right designers?", etc.
I'd suggest that for this kind of discussion Programmers might be the better site to read, for discussions around the broad subject of 'how to hire a good programmer/designer.' (The previous paragraph redacted in response to @Mark Trapp's comment, below). As to the question of 'best resources,' it's possible, though I'm following neither, that either Developer Team Leads, or possibly Interviewing & recruiting, might be proposals worth following.