Start with just one; the one that interests you the most.

Consider going to school for music or finding a good music teacher for your theory/instrument.

I wouldn’t read, I would learn to play. Your interests will expand and meander from there. I think keyboards give you a broader understanding of music than single-voice instruments.

Got shot down for the school, already have a great private teacher.
I have a keyboard but I don’t play it too much. I mainly play bass.
I guess I’m looking for a map of music theory or something. I thought for a couple of seconds when my teacher was telling me about the circle of fifths that that was it. But I just want something to show me the dimensions and functions of music so that I can put what I’m actually doing into perspective.

LAST.FM <—stick that in your address bar.
It is the ‘imdb’ of music. The features are endless on this website. Pandora-like radio by interest or artist, extensive bio on nearly any artist, suggestions of similar artists, suggestions of users that like artists so you can look through their selections and find new music, free mp3s, etc.

Go to college with a music major.

“Every aspect of music” starts with developing listening skills. Try to identify every instrument in an orchestra while it’s playing a symphony. Try to identify every interval of two notes played at the same time. Then three notes in all variations as explained here

http://en.wikipedia.org/w/index.php?search=chord+music

Can you recognize a

http://en.wikipedia.org/wiki/Tristan_chord ?

Can you recognize a genre?

Music is not about reading. First it’s about listening. Then it’s about learning an instrument. Perhaps singing. Then as a third step there’s millions of books. History of music and so forth.

go to wholenote.com for TONS of articles and lessons on theory, and all styles of music (‘cept maybe for Klesmer!)

@TriflinTriscuit: Completely useless, aside from the fact I already knew that site it is in no way helpful.

@mattbrowne: What you are describing is attaching what I already know instinctively about music to established theory, which what I’m already undertaking. I’m looking at this like a scientist whether anyone likes it or not and I can’t seem to find any significant research into music as a whole, considering what we already know about all the components.

yeah forgive me. i confess that i didnt realize you meant actual music theory. to be honest, what would be best is to take lessons and/or theory classes. one of these responses suggested a place you can get theory learning materials – if you’re really ambitious and disciplined you could definitely teach it to yourself.

i’d suggest having a piano because it’s one of those universal instruments that help you learn music theory effectively and what’s more, theory often uses piano concepts to help you learn. you can understand sharps and flats, keys, modulation, chords, scales, etc. with piano pretty easily.

once you learn the basics (which usually takes at least a year) you can learn to do things like write music, write 4 part harmonies and stuff. doing it in a class setting is great cuz you can train your ear with sight singing. good luck!