UNIVERSITY COURSES
Stanford University offers a number of online courses in computer science, licensed under Creative Commons
CS 248 - UNIX Programming, hosted by Community Resource and Instructor Support Program (CRISP) at the Dallas County Community College District in Texas
codecademy: "Learn to code interactively, for free."
Coursera offers a large number of free online classes in a variety of categories, including AI (artificial intelligence), software engineering, systems & security, and theory. Check the categories that capture your interest to narrow your search.
Udacity also offers a large number of free online courses that include computer science related classes. The breadth of courses, however, is limited to the categories of business, design, math and computer science.
w3schools offers classes in HTML/CSS, JavaScript, server-side programming, ASP.NET, XML, and more. The lessons are free, and you can take a certification test for a fee if you choose.
MISC.