Starting fresh with the new forum (I love it btw) I think that this would be a great opportunity to organize the book topics in a way that I think would be beneficial to everyone looking for answers in the forums.
My thought would be to create top level topics for each of the forums.
for example:
IOS 9 By Tutorials ← Forum title
…Chapter 1: Swift 2.0 ← Pinned Topic subcategory
…posted questions and answers for Chapter 1
…Chapter 2: Introducing App Search ← Pinned Topic subcategory
…posted questions and answers for Chapter 2
etc…
Then questions for each chapter would be contained within its own topic which would make searching for answers a lot easier. The reason I suggested this is that there have been times that I was searching through the forums for answers and really found myself overwhelmed with the search results.
Anyways, I love the new forum and I have been a fan of your tutorials/books for some time now as well!
Todd