I personally am a member of one writing group and one critique group. Apparently this is a little weird, but at my writing group we all write. The goal is to get together, encourage each other, work through writing problems together, and write together. We accomplish all of this using 20 minutes of writing, and then 20 minutes of talking.
My critique group is particularly active during on months, and particularly ignored during off months. All of the members participate in NaNoWriMo, and the associated Camps. Three of the four members also participate in JuNoWriMo. An unofficial offshoot of NaNoWriMo that happens in June. During the month a camp or NaNo is happening we take a break while the members write like crazy. Once the month is over we start right back up with one submission of ~5k words per week, and critiquing everyone else's submissions by Sunday of that week.
As someone who is working towards a full-time professional writing career both of these groups are important. The writing group was a great group to start with, getting to know others in the area who enjoy writing as much as I do and GET some of the same problems that I talk about. My SO listens when I talk about my latest writers block, or character motivation problem, but he doesn't write, and therefore can only understand so much. The emotional support of the writers group is amazing, and useful, and real. It's really good for my mental health as a writer.
The critique group is the best for my writing. Having a weekly deadline to edit 5k words has been one of the best things I have ever done to improve my writing turn around. Looking at three pieces of ~5k each with a critical eye has done wonders for realizing exactly what I can do with my own writing for improvements. That's not even touching on how useful my critique groups comments have been.
One of the best things I can recommend for a growing writer is finding and participating in both a writing and critique group. They can help bring any writer to the next level.