Wikipedia article.

One of the Prize Problems named by the Clay Mathematics Institute of Cambridge, Massachusetts (CMI).

A collection of up-to-date links about the satisfiability problem (solvers, benchmarks, articles). A discussion forum is available as well.

A collection of benchmark problems, solvers, and tools. Provides a uniform test-bed for SAT solvers as well as a site for collecting SAT problem instances, algorithms, and empirical characterisations of the algorithms' performance.

Description of the 462 complexity classes and relations between them hosted at Caltech as a part of Qwiki project.

People, publications, prizes.

Course 6.045J / 18.400J at MIT OpenCourseWare with introduction to basic mathematical models of computation, Turing machines, Church's Thesis, time complexity and NP-completeness.

Course 6.045J/18.400J at MIT OpenCourseWare, emphasizing computability and computational complexity theory.

This is a preliminary version of the catalog of NP optimization problems.

Pointers to some survey articles and their authors, by M. Bellare.