I always consider myself a student, for becoming more educated only lets you realize how little you know.  And today, we are all so luck to have so much available to learn online today.  I've listed below a few of my favorite sites.

   An excellent atlas of the universe, similar to Google Earth, but populated by the newest scientific data

   A free online university of sorts from MIT and Harvard

   Brush up on all the basics from grade K-12.  This website has it all for free.

   Read through all the classics and more, one bit at a time.

Flashcard Exchange
   A great site to find flashcards for anything and everything.

   The name speaks for itself.  From health to physics to the environment, these are great documentaries.

   An amazing collection of great talks by the best minds of our time.  Home of the famous TEDTalks.

   A great source for new ideas and inspirations.

   A short video about making the best of your presentations.  Highly recommended!