Honesty requires that I tell you that I have not read this book, only browsed it. At first sight this is purely a reference book but a second look shows it to be a bit more. Each chapter concludes with the details of a closely related set of functions provided by the OpenGL library. One particularly nice thing is the documentation of known bugs in each function where there are any (of course that still leaves the unknown ones).
Each chapter starts with a tutorial on using the functions. These seem to be well written. The authors declare, under the chapter heading, which of them is taking responsibility for the chapter.
If you have experience with OpenGL, or even better if you know you would like to take some time studying it I would happily exchange the review copy with you for an in depth review of the book.
If you use Windows 95/98 you will find a copy of SGI's OpenGL implementation for Windows on the attached CD.