I'm a fan of Whit and a few years younger than she is so I thought her advice could apply to me. As another reviewer mentioned, this is pretty much Whitney's version of Lauren Conrad Style, but it covers more ground than Lauren's. Mostly she talks about creating/finding your own personal style and making it work, but she also gives tips on decorating your apartment, healthy snacks she likes, working in the real world, and throwing a party. She also gives you a glimpse into her life - she uses pictures of her apartment to illustrate what she's talking about and tells stories about her experiences to back up her points. There's no Hills/City inside info, although she references scenes from the shows occasionally.
The bottom line is if you like Whitney and are looking for some fun personal style ideas and advice, you'll like this book. It's a little silly (e.g. the snapshot of her favorite movies), but it was a fun read, and I picked up a few tidbits here and there. If you're not already a Whitney fan/don't know who she is, then you probably won't get much out of this book.