Well, here are two great youtube channels:
Chess Network: http://www.youtube.com/user/ChessNetwork
Kingscrusher: http://www.youtube.com/user/kingscrusher
Both channels have very intresting analysis of games and openings. And also live blitz games with commentary. I've really become a better chess player watching their videos.
Here's a link to comphrehensive readings about chess openings at Wikipedia:
http://en.wikipedia.org/wiki/Chess_opening
And here some statistics from over 2 million games:
http://homepage.ntlworld.com/adam.bozon/stats.htm
And here a huge chess opening database:
http://www.chessopeningsdatabase.com/
If you know other interesting sites on Internet where we can read more about chess openings, please feel free add a comment and insert a link to that site!