After you get married, you need to follow the process on adjusting your status from E3 to a legal US permanant resident. Below is a link to the process. Once you gain LPR stautus, you will be able to live and work freely in the US.
http://www.uscis.gov/portal/site/usc...0045f3d6a1RCRD
One word of caution..if you do intend to live outside the US eventually, pay specific attention to conditions about living outside the US. You may lose your LPR status if you stay outside the US for a long period of time.

