This book is an excellent guide to the varied nature reserves and many other sites of Indonesia not just to birders, but in fact to all travellers interested in wildlife.
The coverage of national parks and remote islands/forests is better than could be found in any other guidebook, and the wealth of detial on transport and accomodation options is impressive.
Unfortunately some of the information in this guide is now dated though - in many areas forests have been cut down, birds eliminated, accomodation closed since the book was written - and of course prices have gone up. An updated 2nd edition would be very welcome, but I guess there is little chance of that happening...
In the meantime, try to get hold of a copy of this book if you plan to visit Indonesia!