I've been following the TruthHistory.blogspot.com Watchtower History blog almost since it was started. It's probably the only authoritative web site dealing with early Watch Tower history. The blog owner has just published a history of Nelson Barbour, one of Russell's first associates. It's an eye opener. I am amazed at the detail and fresh presentation of the facts. There are things in his book you will never seen in a Watchtower publication!
You can read extracts of it on his blog, or you can buy it here:
I can't recommend this book strongly enough. Check out the blog. Go to the publisher's website (the link above) and read more. Buy it! God this is good!