I had the opportunity to read through different books regarding the subject and, while I must admit that each and every one of them has its pros and cons, Operating System Concepts provides the reader with a very solid introduction to the subject. Each chapter is very well structured, mainly on examples from real OS's like Solaris, Linux, Win XP or Mac OS X. Reading through the book, one will notice that some parts are repeated over and over again, but I must stress that I find this a very good thing because it keeps the reader with former issues fresh in their mind. Also, at the end of each chapter, there are some really interesting programming exercises in which the author engages the reader to modify kernel functions from different open source OS's. The code examples in the book are great and very good explained. (mostly C, but Java as well).
Sometimes, the reader will have the impression that the author is advertising Sun's OS, Solaris, because of the big number of examples from it and the good reviews he gives to different aspects of it.
All in all, I definetly recommend it. I will actually buy it for myself. I'm currently reading a library copy.