Hi, 

I've played around with acoustic in my youth but never got real serious. Now I have a yearning to learn to play in my retirement years and am looking forward to the GT method! Haven't owned a guitar in years. I bought a cheap beginners guitar to start with but it's  a 38inch. It seems a bit too cramped for me, (68 years old, 6 foot, 300 lbs. ). How do I know what size acoustic I should be learning with?