In his Inpatient Group Therapy, Irvin Yalom has some simple recommendations about group with crisis clients. They boil down to this: Keep it simple and keep it structured. Let clients know up top what you're planning for group, then do it.
Yalom suggests using a set of three simple, relevant questions. Have clients write down their answers, then pair off and interview each other. Clients share with the group what they've learned from their partner.
I've seen this approach work nicely with dually diagnosed clients. One favorite, asking about jobs--best past job, worst past job, hoped-for future job. Usually makes for a lively group.
Depending upon group members general level of functioning, you may consider skipping the clients-interviewing-clients part and just have clients share their answers with the group directly. But the interviewing offers some good skills practice--listening, remembering, etc.
Generating sets of three questions is easy enough. I'll post some examples soon.