It's hard to give a straight answer here because like most pets, corns' temperaments vary and some will behave completely differently to others.
By "normal behaviour" do you just mean temperament or do you have some specific questions?
In general corns are the perfect 'beginner' snake. They are usually docile and don't mind being handled after they get used to it, with few health worries so they're easy to look after, and they tend to be good feeders. They are primarily nocturnal so some you will rarely see during they day, although many will show themselves no matter what the time of day.
If you are really serious about buying a corn and you want to know everything, the Corn Snake Manual (now 'Comprehensive Owners Guide') which you can buy at
www.cornutopia.com is a good place to start. Otherwise, ask some more specific questions and we'll do our best to answer them.