Best place to learn opening theory?

I'm not talking about videos on chess.com, maybe a website or a book that just goes over all the common openings and their goals for each side. Just a place to mindlessly absorb theory.

Bookwise, GM Paul Van der Sterren's Fundamental Chess Openings sounds like it might be what you are looking for.  There is also an older book Penguin Book of Chess Openings by IM W. R. Hartston which offers a readable survey in a short space.  There are also a number of fairly recent survey series': IM John Watson's Mastering the Chess Openings vols. 1-4, GM Gabor Kallai's Basic Chess Openings and More Basic Chess Openings, and GM Stefan Djuric's Chess Opening Essentials vols. 1-4.

Here is another thread on opening books: Books on Ideas Behind Openings.

If you want to improve opening theory isn't what you're looking for. Opening principals and tactics should suffice for a long, long time.

This isn't just something I came up with of course, these are things I hear repeated all the time from players much stronger than you or me.

(but if you don't like that look at some master games and learn openings from them)

Bobby Fischer said, "Know thy MCO."

"Complete Idiots guide". . .Chess Openings by William Armil (check Amazon: I think it shows some actual pages)). It is an esay to read book that rather than being considered "pedalogical": it cound be (actually is) considered as an "entertainment, relaxing, chess book" intended for up to 1600 players 

I found "chessmaster grandmaster edition" to be the best starting point for me. The academy teaches everything from how the peices move, up to going over and analizing the greats move by move so you can see what they do and why. They dont teach specific openings, just general principles to follow. Its like $9