How do ski boots work?
Does your shoe fit inside the boot? or do you wear the boot itself?
No, you don't wear your shoes under your ski boots, although it might be a good idea to wear a few layers of socks.
Ski boots are designed to be worn for comfortability. You wear the boot itself for support and protection of your feet. They should be fitted properly due to the stiffness of the ankle. Find out more from http://www.mechanicsofsport.com/skiing/equipment/boots.html.