I'm not looking to form a book club here on Cake, per se - I already have one, and would overextend myself if I committed to another. But I have room to do a book outside my club now and then, should there be a few interested kindred souls willing to commit to it.
On the matter of book clubs in general, I've found that the discussion that surrounds a shared reading can be quite fulfilling. My current book club started much the same way when a bunch of people expressed an interest in reading The Silmarillion all at the same time. We're still going 8 years and 77 books later.
The 'forum' format works well. We assign someone to lead the discussion of each book and that person posts a number of discussion topics around the beginning of the month. Then people drift in a posts as time permits, and the discussion lasts about a week, give or take, before it peters out of its own accord. With our 'slow read' selections, we read about 20-25 pages per week and discuss the book in segments each week.