Branching Programs and Binary Decision Diagrams By Ingo Wegener (SIAM, 2000). Errata, solutions to exercises, updates on open problems. http://ls2-www.cs.uni-dortmund.de/monographs/bdd/

A Compendium of NP Optimization Problems By P. Crescenzi and V. Kann; KTH Stockholm. A continuously updated version of the appendix from the book "Complexity and Approximation" (Springer, 1999). http://www.nada.kth.se/~viggo/wwwcompendium/

Introduction to Circuit Complexity: A Uniform Approach By Heribert Vollmer (Springer, 1999). Excerpts, errata, bibliography in BibTeX format. http://www-info4.informatik.uni-wuerzburg.de/CC/

Introduction to the Theory of Computation Michael Sipser (PWS Publishing) Table of contents, errata. http://www-math.mit.edu/~sipser/book.html

Algorithms and Complexity A downloadable textbook by Herbert S. Wilf. Each chapter is available as compressed PostScript or PDF. http://www.cis.upenn.edu/~wilf/AlgComp.html

The Art of Computer Programming (TAOCP) By Donald E. Knuth. Bibliographic details of the published volumes (1-3, various editions and translations) and on-line beta versions of parts of volume 4, "Combinatorial Algorithms". http://www-cs-staff.Stanford.EDU/~knuth/taocp.html

Data Structures and Algorithms with Object-Oriented Design Patterns in C++ A web text by Bruno R. Preiss of the University of Waterloo. http://www.brpreiss.com/books/opus4/html/book.html

Handbook of Algorithms and Data Structures By Gaston H. Gonnet and Ricardo Baeza-Yates. The preface, table of contents, index and all source code of this handbook. The main goal is to make available through Internet the source code of many algorithms (in C and/or Pascal) that have been already tested. http://www.dcc.uchile.cl/~rbaeza/handbook/hbook.html

The Art of Computer Programming By Donald Knuth. Homepage of the classic text. http://www-cs-faculty.stanford.edu/~knuth/taocp.html