Not for groups, but for individual people. When I talk about topics of general interests for rationalists with someone else, I often introduce them to less wrong. I tell them something along the lines of "There's a community of like minded people who likes to discuss similar topics on LessWrong.com".
I think something similar, i.e. organic recommendations can work for larger groups, you just have to use a different format. One idea would be to give a presentation and then add a final slide recommending to check out the website.
I think I'm slightly behind you, at least in the context of exercises. I recently completed all the age word problems on the exercises section.
I've started the exercises from scratch (I'm bit more of halfay of them I think) and after that I'll start the all the playlists from algebra from scratch.
I know there are a lots of videos, but I'm sure understanding the basics of math will help me tremendously. I'm a self learner with poor math background. I want to fix that.
your waywo tag link is not working.
I'm currently working on improving my math skills through khan academy.
Edit: you need to add discussion before /tag
Good advice, I'm actually looking to start some similar projects. As you said feedback is very important, but for some of us it's difficult to find rationalists in our area to share these experiments. I would like to see some sort of online group where we can share and discuss practical ideas, or get advices from time to time. A forum would probably be enough, and I can create one if there's enough interest.