Microsoft released a new How Do I video on the LightSwitch Developer Center on controlling user access in a LightSwitch app. In this video you'll see how to set up security to control user access to parts of a LightSwitch app by specifying sets of permissions on Screens and Entities and checking those permissions in code.
You'll see how to test these permissions during debugging as well as how to set up users and roles in the system once deployed.
More Videos: Lightswitch "How Do I?" Videos