It's hard to quantify the value of the internet. For those of us lucky enough to have access, it can mean unlimited opportunity to learn the skills we need to learn. Every day new innovations are born that have the opportunity to change the future.
Two sites that I recommend are Quora.com and TED.com, both for the same reason. They are great thought-provokers. I'm still a fan of reading books, but these are both essentially condensed versions of books. The wisdom that used to be written down in book form can now be expressed to similar levels of audience without near as much effort.