wikis and so forth

I just put a group with a mission up on a wiki and am wondering how it will work. So far, not too well. It's hard to figure out where the public discussion arena is and gently herd talk toward that area, so that newcomers can find things. People have referred SocialText, and someone just said that SocialText was 'bare bones' and recommended Jot. Geek friends have recommended TikiWiki. I've been looking at/playing with Zwiki. Sure are a lot of products out there...