I have heard how giving you are in so many respects of music schooling and I must say that I am impressed. You remind me of the pure idealism that we had in starting Apple. If I were young, with time, I'd likely offer to join and help you in your endeavours. Keep making people happy, not just in their own learning, but in the example you set for them.
As a beginner, it is best to avoid making a pawn shop, flea market, or yard sale purchase unless you are shopping with somebody who has experience in purchasing a guitar. Having never purchased a guitar, you may not know what to look for in terms of damage or guitar quality. With that being said, a local music retail shop is your best bet. You may also shop online with a reputable company, although be sure to review the business’ return policy.
Minutes 30-60. Practice making the basic 5 shapes. This is probably the hardest part. You gotta put your head down for 30 minutes and remember the chords that are demonstrated below. Once you start getting these shapes down, adding to your portfolio will be easy. You can even experiment with adding and removing fingers– you’ll find a lot of cool sounds here and you’ll continue to discover these for years to come.
Electric tuners are easy to use and very accurate. Hold it to the guitar and pluck the high E. The tuner will tell you if the guitar is "sharp" (too high) or "flat" (too low). Pick each note and tighten the string to make it go higher, or give it some slack to lower it. Make sure the room is quiet when using a tuner because the microphone on the tuner can pick up other sounds.
Intermediate Guitar Class - Open to all ages, from age three to one-hundred sixty-three, but an audition or permission from the instructor is required. This class is intended to be challenging. Topics covered may include movable bar chords, song forms, repertoire development, fretboard mapping, improvisation, and other advanced techniques. New classes start every month and may be repeated as often as you like. Cost is $85 per month (4 hours).