How Stuff Works @ http://www.howstuffworks.com/

A pretty good site to visit for those whom are curious about things (they even have animations to help depict the matters!) But the animations also make you wait longer to view the pages.

Sharky Extreme @ http://www.sharkyextreme.com/

and Tom's Hardware @ http://www.tomshardware.com/

Two helpful sites to visit for those whom are interested in building or upgrading systems, and buying new technology toys. I think Tom's Hardware is more complete and easier to understand.

The C++ Why Page @ http://graphics.cs.ucdavis.edu/CppNotes/Cpp-Why.html

and The C++ Standard Library @

http://www.autoobjects.com/Home/Teaching/CmpE_126/CmpE_126_Lectures/C___Standard_Library/c___standard_library.html

Two must-visit sites for those whom use the C++ programming language. The C++ Why page is short but helpful, while The C++ Standard Library is something hard to understand.

Sun's JAVA tutorial @ http://java.sun.com/docs/books/tutorial/index.html

and UC Davis' JAVA tutorial @ http://heather.cs.ucdavis.edu/~matloff/Java/JavaIntro.html

Two must-visit sites for those whom use the JAVA programming language. I think the UC Davis one is much more concise and easier to understand than Sun's, even though Sun did developed JAVA.

Also check out the following two sites:
Common JAVA errors @  http://www.skylit.com/javamethods/appxf.html

and the JAVA API Specification @ http://java.sun.com/j2se/1.3/docs/api/index.html

The Stanford CS Education Library @ http://cslibrary.stanford.edu

A site that distributes free information on pointers and memory, lists and trees, the C and Perl languages, and using UNIX.