Wikipedia is great for research and I often go to YouTube for video tutorials. But where do you all go if you want to go more in depth and learn a new skill or subject?
India has a "Technology Enhanced Learning Program" called NPTEL. It includes video lectures for courses on many kind of engineering programmes, and everything is en English.
Not too long ago I wanted to get a little deeper on analog electronics and found their classes where more useful for me than the ones in OpenCourseWare. MIT's program I found better for Computer Science.
Definitely depends on the topic. Typically I search for a forum dedicated to the subject. The forum's search will be great for finding generations of people asking how to do the same things you're now wondering about. And forums provide a living knowledge base rather than a static one.
http://safaribooksonline.com rocks. Thousands of books in pdf format for you to read. I am lucky that my company provides free annual access to it though.
UC Berkeley Webcast/Courses http://webcast.berkeley.edu/courses.php
MIT's OpenCourseWare http://ocw.mit.edu/index.htm
Mozilla's School of Webcraft http://p2pu.org/en/schools/school-of-webcraft/
Google Code University http://code.google.com/edu/courses.html
Khan Academy http://www.khanacademy.org/
Ontwik http://ontwik.com/
Code School http://www.codeschool.com/
There are also a lot of startups focusing on tutoring&co, like
http://www.skillshare.com/
http://edufire.com/
http://www.tutorspree.com/
http://www.udemy.com/