What days do you do what, and how often are you doing cardio? For somebody who is new to this, I am quite impressed on the way you have planned out your routine (complete with sets)! I am confused about your labeling of the days, ex. push day, bench day 1, 2, etc. Anyhow I will wait till you post to clerify your workout schedule before I throw my $.02 in.
Here are some good lower back workout ideas:
http://www.bodybuilding.com/fun/exer...cle=Lower+Back