I watched a couple of times NHJ's 10 years younger program. Despite it was fairly good I didnt' really stick to it because of the cosmetic surgery involved (I make an exception for dental surgery) and because I had already absorbed a lot of information through "What not to wear".
I bought this book based on viewing the first few pages and the cookbook concept totally appealed to me.
The layout is very pleasant, well sectionned into trends where you can cherry-pick elements of inspiration to create a whole outfit. As she mentions, rightly so, trends have been more or less the same for the last 10 years under different names. It's particularly obvious in UK where high-street brands closely draws off from famous designers.
I absolutely loved the styling suggestions charts that can be easily applied with what you already have in your wardrobe and maybe didn't think of. She really teaches you how to pull a whole look together your own way. The Winter/Summer suggestions (or how to make the transition from one season to the next for each trend group) are simply genius. I'v often found this transition difficult for no clear reason so this part was very helpful to me.
The only things I didn't like so much about the book were the body shape and make-up tips. Both could take a whole book and many trial and error sessions if you know nothing about it. Body shape is the backbone of great style in my opinion, so I'd recommend you also get other books dedicated to it (e.g. Trinny and Susannah, Bradley Bayou). The women shown to present the various suggestions are not perfect UK8 models which may not be appealing for some though they're real women. I much appreciated the fact that the author states that all rules can be broken. And as usual, books do help but the hard work's still up to you!