Agree on location, frequency of meetings, submission deadlines and methods, etc.
Follow WSW policy: a nonmember may attend up to two sessions before being required to join WSW or drop out of the group.
Every group member, including the coordinator, should regularly submit work for critique.
Decide whether members should have the option to read from their work (recommended) and for how long (typically five minutes or so).
As a group, adopt procedures that decrease the potential for lengthy discussion of comments (some groups ask that the member whose work is being critiqued not respond, unless asked a question, until all others have commented).
When you submit work for critique, let the group know what kind of critique you want. It can range from the ultra-detailed (a line edit) to more general observations about certain elements of craft (e.g., theme, plot, setting, characterization, dialogue, etc.).
When you critique someone's work, try to honor his or her request (see above). Be specific. Start with the positive. Say what works, and why. Next, say what could be strengthened, and how (but please don't rewrite the work yourself). Be candid but kind. "Gotcha" is for political campaigns.