I pretty much taught myself to play guitar, except for some lessons from an old lady when I was a kid.
It's so much easier now,with the Internet and apps and such.
I used to go into news agents and read lessons and music in magazines and try to remember them then go home and play them as I couldn't afford to buy them. Sometimes I'd have to back heaps of times to learn a Megadeth or pantera solo I couldn't work out.
If your gonna learn guitar get an ipad or similar and get an app call guitar pro, you can get it in your computer too but it's more expensive.