I used to think the lenght of the fingers mattered until I saw a video of a little chinese girl named Li Jie play the Caprice # 24 by Paganini.
I have tried to learn that, but its too brain-scrambling, and besides to learn rock all you need is a book that has the chords to your favorite tunes, and the words of the song sort of guide you to the next chord change. Few or none of the greats, ever learnt notation, and those who do get stuck too long in that area, (learning notation) can't do anything else. Unless you wanna be a teacher in a college, I strongly advice to not even try. If you can memorize how to play three chords, you will be able to play at least fifty songs, and if you can learn seven chords with three variations, then you can play any song ever written. This gives me an idea....
Shit like this just amazes me.. a kid can be this good and here i am sucking badly at guitar lol.. http://youtube.com/watch?v=owAj5LiXG5w
I was in the same situation! Now it is year after, I am far from reaching perfection but it is great and sometimes I still amaze myself I am self thaught player. In the beggining simple youtube videos might help a lot. And don't worry, it feels very hard at the beggining, but soon you will start getting quickly better and better.