In the recent past, there have been problems reported with MWA, but every organization has problems, and MWA's were blown out of proportion. It's a good organization. I also belong to International Association of Crime Writers which gives me a chance to meet overseas colleagues, and Sisters in Crime is a terrific group for both writers and fans. Read, read, read in the genre. Write, write, write, everything you can.
Writing is like being a professional musician.
You have to practice the scales over and over so that when you sit down to perform, you don't have to think about where the notes are. I've never had any experience with writing critique groups, but if you trust your colleagues, it's very helpful to have astute readers who can help if you go astray or get stuck, or don't understand what you're trying to say. Publications, electronic or otherwise, that talk about writing can be helpful by giving you ideas you might not have thought of, and help with technique. I find Dorothy L very helpful in getting a sense of what readers care about, what they hate or find trite. My agent is helpful, too, but I think he's probably too kind.