#1
Hey, I'm just wondering. Basically I'm looking to use what I know on guitar and looking to improve my music theory as well. Any of you out there making money teaching instruments know what kind of pay is open to any market of tutoring (whether it be by music store or privately).

Also another thing importantly... what are all the things I should know before tutoring guitar theory, scales, chords. I know I can go advanced to a certain point, but I want to know what most people are looking for, outside of teaching guitar to people who want to rock.
#2
Forgive me if I misunderstood what you meant but that first bit you wrote made me think you want to teach to improve your theory. This is something I would advise against, it wouldn't really be fair to your students either if they are paying you.

How much you can make is going to depend on your experience and location. You can see anything from $20 to $60+ an hour, it all depends on who the teacher is. Just make sure you can justify what you charge.

Now as far as what you should have a grasp on when it comes to teaching. You should know ALL of your basics like the back of your hand.

By basics I mean the following:

Names of your notes and their locations
Major and minor chords in different voicings (barre chords, open chords, inversions, etc), Scales- at least your major and pentatonic scales and in different keys
Proper technique - Posture, thumb placement behind the neck, holding a pick properly and NOT anchoring with the picking hand.
Depending on the kinds of music, different picking techniques. Proper fingerstyle to alternate picking, it seems to be something a lot of teachers overlook unless a student struggles with it.
As far as theory goes, perhaps your circle of 5ths and why it works the way it does. This would also mean you would most likely know your sharps and flats of different keys.

Most people either want to learn to make their own music, or to learn to play their favourite music. Your job is to provide them with the opportunity to do either as a teacher.

It also never hurts to make what you're teaching fun. It will keep students motivated if they enjoy what they are learning.

Hope this helped dude, if you do decide to go ahead with teaching, the best of luck to you!
#3
Something I might add is to make sure you truly want to help people become better guitar players. When I started teaching I made many mistakes but I always had a passion for it and eventually that will shine through alongside the knowledge you are imparting. This will inspire your students. Good luck!
Andy