To go live, put your shop into "Down for Maintenance" mode in the admin area. Be sure to add your IP address to the list of allowed addresses to get into the site for previewing.
This can be done easiest by renaming "store_new" to "store". (You'll have to rename "store" to something else first.)
Test it to be sure that things are operating as desired. If you have small problems to repair, turn "Down for maintenance" on and off again as necessary.