Jeff, I am currently leading 10-14 adults through the Opening the Book of Faith book.  It is not an established class, just one I built around this resource.  I have found the leader's guide helpful as "back up" but we have had lively discussion that has lasted most of our hour and a half class simply started by the question, "What did you think about this chapter?"  And then they are off!  I have used a few of the activities in order to get them into smaller groups and looking at some of the suggested Bible passages.  We are the doing the "class" in four weeks, one for each chapter and in our final class tomorrow night we will break into groups and actually do some of the studies in the back of the book.  I think you have to pick and choose what you do from the Leader's Guide.  I think you have to choose a focus of the session and do those activities or something close to it, and trust that the participants will get what they need from the rest of the chapter.  If you have more than four weeks, you could spend several weeks on each chapter.  We did it quickly because it was summer and I wanted to see how it was going to go over in our congregation.  These 14 have loved it!  We will be doing more in the fall.