If you are looking a an excellent free source of educational content for your computer lab/learning center then WatchknowLearn is the resource for you.
WatchKnowLearn believes that everyone should have the same opportunity to learn. They believe that the best way to make this possible is to organize into one, super directory the hundreds of thousands of good videos currently available on the Internet. To make this a reality, they invite teachers, instructors and educators to suggest videos for inclusion into their directory, and then to review, approve, and assign those videos into appropriate categories using a wiki framework and philosophy. The videos are the highest quality found on the World Wide Web, cover all major educational topics from elementary to secondary schools (or age range 1 – 18), and are Kid Safe!