I recently visited Dani Shapiro's site and she talked about this--writing has to come before blogging, although blogs are great distractions when the book is going south...
 

Mary,

Thanks,I learned from chatting with Chris Anderson about his experience in writing "The Long Tail" that you have to resign yourself to long periods of down time. That's hard for me to do, but especially with the depth and breadth of the topics in Content Nation I have no choice but to do so. But almost done now, I have Chapter 10 and a short Conclusion yet to come. Check it out today at Contentnation.com!