How do I go about becoming an officer in the army?

Ok I just enlisted into the army as an 91k armament repairer. I have a BA degree so I'm going in as an E4...ok your prolly like why did I not go officer from the start...well I want to get experience in the enlisted side that way once I do become an officer I can related better with the enlisted soldiers under me. My contract is for 4yr and do plan to do the entire 20 yr( I'm 23 now) what steps do I need to take to become an officer? I want to do at least a year or two before I go officer, but def before I complete my first 4yrs... What steps should I take? I leave for basic July 28..please leave all experiences and info thanx you can also email me @ midgetteboy12@aim.com