"WordNet: An Electronic Lexical Database" is available from MIT Press. It includes articles describing the design and contents of WordNet, an update to Five Papers on WordNet, as well as papers reporting on research done with WordNet in the areas of linguistics, information retrieval, word sense disambiguation, semantic concordance building, text analysis, and knowledge engineering. The book and CD-ROM can be purchased directly from MIT Press.
The most recent WordNet documentation is available online.
Many thanks to Joseph Rosenzweig of The University of Pennsylvania for initially putting together a comprehensive WordNet bibliography, including links to the papers wherever possible. This was maintained by Rada Mihalcea (2000-2005) of North Texas University, and is then by Andreas Csomai (2006-2007). At the present time, the bibliography is growing faster than it is possible to maintain. However, it is still critical that researchers remember to cite WordNet, as publications are critical to obtaining funding for WordNet maintenance, future releases, and enhancements.