Salvador/Skill tree

Gun Lust
Focused on switching weapons, reloading, and gives Salvador various gun abilities.

Rampage
Focuses on extra ammunition and Gunzerking all or most of the time.

Brawn
Focused on physical toughness by soaking up damage due to massive health generation and also gives Salvador physical abilities.

Visit http://www.borderlands2.com/us/skilltree/gunzerker.html for skill trees.