I think that the most important thing to have when you learn to play a guitar, or any instrument for that matter, is patience. A lot of my friends picked up an instrument and thought they could be good at it on the first try, and they gave it up soon after.

Next, I would suggest getting some tabs, but make sure they're easy. I mean, you can't just start with something like Stairway to Heaven by Led Zeppelin. I would suggest getting some songs by simpler bands such as Fall Out Boy, My Chemical Romance, or Green Day, even if you don't like them... I say this because many of their songs contain simple music to play.

And last, practice is really really important. Practice a lot...and I mean a LOT.

Well that's all I have to say...hopefully I was of some help.