I was a little concerned about this book at first because there have been a few attempts to apply "brain chemistry" theories to various activities, including teaching. I have been underwhelmed in the past by books about learning to be a better teacher through understanding how the brain works. Not that it's not a worthy pursuit, but a lot of the books on the topic are badly written. Not so with Cron's book on writing. While I could have done without the explanations of what the human brain responds to, and focused purely on Cron's specific advice to writers, the brain-theory stuff is not overdone. There's enough information about how humans process information to be useful without being overwhelming.
Cron writes with wit and humor so reading the book is a pleasure. It feels like being in a class where she is speaking directly to you. There are plenty of amusing anecdotes and asides that make you feel like she's right there in your living room - or wherever you happen to be reading. While the book isn't all that long (just over 200 pages), you should take your time reading it and focus on the information she's giving because each page is dripping with pearls of wisdom (I know, mixed metaphor and all that). Some craft books can be devoured in a single sitting but I would recommend taking time over this one and thinking about applying Cron's thoughts and techniques to your own writing. Maybe reading a chapter a day and mulling over it would be a good approach. There's not a lot of craft books that I go back to again and again, but I think this will be one of the ones I do.