The Elder just sent me an extraordinary email with a link to M. Avrum Ehrlich's website, where he has a complete pdf copy of his book, Leadership In The Habad Movement available for free download. I think this is Ehrlich's best book to date on Chabad, and it's well worth reading.
He seems to have new book on Chabad in the works, as well.
Update 12-31-2014 – Ehrlich's website is no longer functioning. So here's the book as a PDF file: