A good introduction into music theory?

[BH]

I've been playing the guitar for about a year and a half now. As time has passed, I've gotten better and better. As my skills have improved so has my desire to understand music. I've tried searching the internet for help but that hasn't worked out very well.. partially beacuse there are too many distractions and I can't stay focused on the task at hand...Anyways, are there any books , written by very distinguished, authors that could be of help? I just need something to get me started. Something to build a very basic foundation. I plan on taking lessons sometime in the future but in the mean time I'd like to have some sort of guidance.
Also, I really enjoy classical music =D.. If that helps

 

[kucletus]

Here are a couple of college-level textbooks - I would suggest used copies from Amazon:

Robert Gauldin - Harmonic Practice in Tonal Music
Stefan Kostka & Dorothy Payne - Tonal Harmony
Miguel Roig-Francoli - Harmony in Context

You might also try the "Music Theory for Dummies" book, found in stores like Borders, Barnes & Noble, etc.

There are also some great web-based resources to get you started - check these out:

www.musictheory.net

www.teoria.com (ear training)

www.emusictheory.com