I've read a few SharePoint books, and I've poked through even more. Most of them, it should be no surprise, aren't really of much worth to the most dedicated of us. All too many books - and I find this especially so for SharePoint - seem to be mere paraphrases of what's already available on MSDN; hardly worth paying hard earned pigeons for.
A couple of months ago, after a pretty hefty pause from all technical offline references, I spent some time reading Building the SharePoint User Experience. Originally thinking this was going to be another "here's a list - it can hold stuff, but don't ask me how" kind of book, I was sort of a skeptic. What I found, however, was that it actually went pretty deep in subjects I had been pondering myself, not to mention all the stuff I had no idea about.
The best part, though, is the fact that it dares point out all the horrid, horrid stuff you're bound to encounter with SharePoint. The stuff that many others will happily ignore, so as not to displease anyone. Originally being a C++ dev, I'm used to stuff being awkward, ugly and downright painful - so I want to be told, rather than stumbling ass backwards into every trap there is. In short, this book saved my behind a few times in a library I was deploying at the time, so I feel I'm doing you a favor by giving you a heads up here.
The author (Bjørn Furuknap) also maintains a very helpful blog, at furuknap.blogspot.com, so you should at least give that a go.