Esgallindeion is away for awhile and we don't know when he joins in. I think with his experience he's the best to answer such questions, but meanwhile may I share my experience?
It's been only some 6 odd months since I've been learning and all I've learnt from is the internet: I've had no teacher so far, and now feel confident to be able to go a long way before I'll need one, and that too is for the more intricate techniques involved especially in the electric guitar.
I began simply be learning chords - the basic open chords to begin with, and proceeding to some of the more difficult barre chords. And almost for the first 1-1/2 months I hadn't learnt a single song but had only been practising chord changes, increasing the tempo gradually. Only afterwards I started learning songs and learning newer and more complex forms of the basic chords. Now, I can play almost any song as I'm now familiar with all the chord shapes that exist and even can shift rapidly between those.
Not to mention, I was also learning a lot of the music theory behind these.
I'm not sure if any personal experience suits others but I think mine was a good way with a solid foundation.
Many times I've lied, many times I've listened
Many times I've wondered how much there is to know...
Mellow is the man who knows what he's been missing
Many many men can't see the open road...
Many is a word that only leaves you guessing
Guessing 'bout a thing you really ought to know...