I am giving a brief information about the the self help group I go to. It organised by someone called Paul Cunningham in London. By organise I mean he took the responsibility of getting the people together. Me and few others decided to join his group and help him run it. It occurs once every month, on a sunday. everyone is informed by email. The total number of members is 22, though not everyone may come on a meeting. I remember the smallest size we had was 5, the largest 17. When it started, it had 6 members. I joined 2 months after, when i heard about it from a friend of mine (member of the BSA-British stammering Association).
We meet at Paul's house who kindly decided to give his living room to that meeting once a month. One is chosen as the moderator that meeting and then he introduces the new members if any. Anybody who is new wishes to introduce themselves can do so. We all sit in a circle facing each other. Then anybody who wishes to practise saying their name can do so. They raise their hand and the moderator asks him/her to speak. That way there is no confusion.
Then we talk about what happened that month, anything they want to share , regarding some problems they faced because of their stammer, frustuations, hurdles, people's reactions etc. Also they share what things the have done despite/overcoming their stammering (like someone gave a presentation of his college project, interviews, made a phone call etc) that month. This usually last 15-30 mins.
then for each meeting we chose different topics. Different topics we did discuss during our monthly meetings are:

a) interviews: We discuss the problems we face when we go for interviews. what are our fears. how we react. We do mock interviews. We share what things help us do well in the interviews.
b) future plans: What we plan to do in the future. what is stopping/holding us back. How much we think our stammer is holding us from our future plans/dreams. what possible things we can do despite our stammer
c) Relationships: How is our relaiotnships woth our spouses, brothers and sisters, parents, colleagues, classmates, neighbours etc. How is it being affected by our stammer. how they see us. How they see our stammer. How to improve relationships despite our stammer.
d) Work: Interaction with colleagues. bad experiences, good experiences
e) Phone calls: How much making phone calls is problem. What we do, how we react.
f) Speaking circle: Participants would stand up in front of a semi circle of people and speak about any topic for 1-5 minutes. This is to practice talking in front of poeple. But sometimes , someone may choose just to stand in front of the peolpe and say nothing. This may sound strange, but standing in front of the group of people for 2-3 minutes, silently, looking at them and they looking at you is not easy specially for a stammerer. For a stammerer siltent is very frightening. So people practice just to stand up in front of a group of poeple siltently first. Once they are comfortable, they start talking about any topic they like. Its main purpose is not to be a good speaker, but to practice being comfortable talking in front of a group of people, so quality of talk, topic, quality of presentation is not important. We are always obsessed with being perfect/fluent speaker so the exercise is to be comfortable without being perfect/

All these discussions last 30 mins to 1 hour. People raise their hand to give opinion. someone can give a comment on what the other said. At the end, people discuss the positive things they should do to overcome the problem(like phone call fear, not being able to communicate in a relationship, fear of giving presentation), so that not only we discuss our issues, fears etc but also leave the meeting with a postive mindset.
If someone does not want to talk , he is not forced to do so. He can remain silent and listen to what others say. However he/she is encouraged by others to speak.
Everyone is provided equal opportunity to speak by the moderator.
It is a good opportunity for everyone to practice the speech technique they learnt in a speech therapy. I have not gone to any speech therapy so I practice speaking slowly in the meet. Everyone is patient for the speaker to speak slowly and wait for him to finish even if he is havng a big block.
Then near the end of the meeting, a moderator for the next meet is chosen, usually someone volunteers to be the moderator.
The meeting last 2 hours roughly.
then sometimes we decide to go to a restaurant together (not always).
To keep the meeting running properly, everybody should be punctual.

Also we keep in touch with members by phone, emails or meet up sometimes. When I have a bad day (like stammers more while talking to my boss and feeling low), i call up or email or meet up one or more people from the group and talk about it. We provide word of encouragement to each other. or suggestions which helped us. Its a support network.

Hope the information has been helpful. Please write back letting me know. What kind of information would you like , what kind of help do you expect, what things you want/can to do in forming a self help group. Remember a self help group can start with just 2 people . Once you start it, people will join it. Number is not important, what you share and get out of the sharing is important.

BTW, here is a good resource link about stutter/stammer:

http://www.mnsu.edu/comdis/isad9/isadcon9.html