Every so often I am asked about books on Beowulf/HPC clustering. The good news is there are books available at several levels. The bad news is no one book covers everything because the number of topic areas is so vast. To make your search easier, I have surveyed all of the cluster books I know about. I have not included some that are out of print or don't really discuss HPC. Some of the books are dated, but still contain good general information. Others are just plain old, but are included here for completeness. If you know of any other books, please add a comment. My list is as follows:

Engineering a Beowulf-Style Compute Cluster by Robert G. Brown
A freely available book (pdf) that discusses building and designing Beowulf style clusters. Robert Brown is a long time contributor to the Beowulf/HPC cluster community.

Building Clustered Linux Systems by Robert W. Lucke
A very good overview of cluster computing methods and hardware. The book provides a rather wide coverage of options, but does not dive too deep into any one approach. It is somewhat Hewlett Packard focused as author works for HP. (648 Pages) ISBN: 0-13-144853-6

HPC For Dummies (an ebook) by Douglas Eadline
A very short introduction to HPC, but not for dummies either! The ebook is available for free from Sun Microsystems after registration. The book provides backgound and best practices. (authored by yours truly)

Beowulf Cluster Computing with Linux, Second Edition by William Gropp, Ewing Lusk and Thomas Sterling
Updated edition, now edited by William Gropp, Ewing Lusk (in addition to Sterling). Provides a good, but high level view of Linux clustering. This edition includes ROCKS and OSCAR coverage plus other important issues. (504 pages) ISBN 0-262-69292-9

Beowulf Cluster Computing with Linux by Thomas Sterling
The next book after the original "How to Build a Beowulf" by Tom Sterling (see below). Coverage is much expanded, but now very high level as chapters are written by key players in the cluster community. (536 pages) ISBN 0-262-69274-0

Beowulf Cluster Computing with Windows by Thomas Sterling
Approximately 75% of the material is the same as the Linux book by Sterling (no file system coverage). Newer versions of Windows HPC Server 2008 make this a bit dated. If you need Windows clusters, you may want to start here. (488 pages) ISBN 0-262-69275-9

How to Build a Beowulf by Thomas Sterling, John Salmon, Donald J. Becker and Daniel F. Savarese
The first book on Beowulf cluster computing. Published in 1999, it is now quite dated. Both hardware and software have moved past the text. It does provide good coverage of the issues facing the cluster builder. (261 pages) ISBN 0-262-69218-X

In Search of Clusters by Gregory Pfister
A good (and very technical) book about the advantages of cluster architectures. Also provides a very detailed analysis of programming models This book seems to be out of print. Worth reading if you can find a copy. It does not cover Linux Beowulf clusters. (608 pages) ISBN 0138997098

High Performance Linux Clusters with OSCAR, Rocks, OpenMosix, and MPI by Joseph D. Sloan
O'Reilly's second attempt at a Linux cluster book. Many feel this second attempt has missed the mark (again). Also note, the The OpenMosix Project has officially closed as of March 1, 2008. (367 pages) ISBN: 0-596-00570-9

Linux HPC Cluster Installation An IBM Redbooks publication
This document focus on xCAT (xCluster Administration Tools) for installation and administration. All nodes and components of the cluster, such as compute nodes and management nodes, are installed with xCAT. Dated material.