About 18 months ago I decided that I wanted to learn to play guitar. Let's call it a "whim".

I borrowed my brothers electric, which he had given up on, and as the wife decided she didn't like the sound of me practicing, I played it without using the amp. I told her I wanted to buy an acoustic and she responded by telling me that I wasn't buying one only to have to sell it again in a month. So, I struck up a deal with her and she agreed that if I could fumble my way through 10 songs, she'd let me get one.
I thought about lessons but due to what I considered to be a ridiculous price and stale teaching techniques, I decided to teach myself.
I had already decided that I didn't want to learn scales and didn't have the patience to learn lead guitar, so set about learning chords. I figured the best way to do this was to start with the basic ones that I could half get my fingers around - A, E, D, G, C, Em, Am etc, and taught myself to play simple 3 chord soongs.
After I had ruined all of the classic, Knockin' on Heavens Door, Who'll Stop the Rain etc, the good wife allowed me to buy an acoustic. I grabbed a cheap arse Yamaha F310. It's been a fantastic guitar and my play list now extends past the 10 songs. Through a lot of patience and efforts I've even managed to get my fingers around barre chords.
The best thing of all, is that Casey loves it when I play nursery rhymes and Wiggles songs. This is the reason I started learning to play to start with. All I have to do now is stop the dog from howling when I sing.... err, attempt to sing.
The moral of the story is this;
If you are going to teach, find out what it is your students want to learn. I still have no desire to play scales, practice stupid finger exercies etc. All I wanted to be able to do was strum a few songs. Some people want to learn to play solos and lead guitar. Teach them what they want and they'll keep coming back.
There is a bloke on YouTube called Justin Sandercoe. He's a Tasmanian lad who now lives in the UK. Of all those offering free lessons on YouTube, I find his to be the most like the kind I'd like to get if I was paying someone:
http://au.youtube.com/user/JustinSandercoeSongs