First and for most, this game is amazing!!! I find myself forgetting i have a main quest and get so caught up in the side quests, next thing i know 3 hours have gone by

Im confused what the dragon souls actually do when you kill a dragon. I mean, i don't notice any change in my character or in my shouts. Whats the purpose of them.
Also, is there a good guide on this site for properly gearing and leveling a "warrior" class character?
Most appreciated!