Dictionary of Algorithms, Data Structures, and Problems  -  Definitions of algorithms, data structures, and classical Computer Science problems. Some entries have links to implementations and more information.

http://www.nist.gov/dads/

The Stony Brook Algorithm Repository  -  This WWW page is intended to serve as a comprehensive collection of algorithm implementations for over seventy of the most fundamental problems in combinatorial algorithms.

http://www.cs.sunysb.edu/~algorith/

Algorithms Courses -  Links to courses in algorithms maintained at various university computer science departments.

http://www.cs.pitt.edu/~kirk/algorithmcourses/

Algorithms in the Real World -  Notes for a course at Carnegie Mellon University.

http://www.cs.cmu.edu/~guyb/realworld.html

Analysis Of Algorithms -  Home page of Analysis of Algorithms, with links to research in analysis of algorithms, people, events, references, etc.

http://algo.inria.fr/AofA/

Web Data Structures and Algorithms - Web Data Structures and Algorithms. 

http://cgm.cs.mcgill.ca/~godfried/teaching/algorithms-web.html

Data Structures -  Lecture notes by Steven Skiena.

http://www.cs.sunysb.edu/~skiena/214/lectures/

Combinatorial Algorithms -  Course material, syllabus and notes for a course at Combinatorial Algorithms course at San Diego State University.

http://www.eli.sdsu.edu/courses/fall95/cs660/

Data Structures - Introduction to data structures by Peter M. Williams. (University of Sussex 2006)

http://www.informatics.susx.ac.uk/courses/dats/dats.html