I've been playing guitar for four months now (I have a classical, but I play acoustic type songs).
I've been doing hammer-on exercises almost everyday for about a month.

I know NOTHING about music theory.

My questions: I'm a noob in theory, where do I start?
Thats a very good site, some stuff though regards piano which probably isn't really important as a guitarist, unless you like sheet music.
Agile AL3000
Douglas WRL90
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I found it really helpful taking an AP Music Theory class in high school. Depending on what you're interested in, maybe take a music class if you're currently enrolled in school. One of the most useful things I learned was how to listen to songs and recognize chords/intervals/progressions/modulations/etc. You can of course do this on your own with the proper resources, however teachers are generally beneficial with this kind of thing.
Yea, I'm actually in college. I'm an engineering major so it's been a challenge balancing life, guitar, and school. I actually plan on taking Intro Music Theory as a Pass/Fail class next semester depending on how difficult I expect my workload to be.
can always take private lessons, most offer 30mins or a hour. That can at least get your foot in the door, reading something might lead to questions it's good to have someone give ya the answers as well as critique your technique!