Home court advantage (found in Office --> Jobs) indicates the level of an advantage your team receives by playing at home. These ratings range from A+ (best) to F (worst) and are relative to all schools in all divisions.
As your team progresses through the season, your home court advantage can change based on the performance of your team. If your team starts off the season at 10-0, you can bet there will be a buzz on campus and it will be hard to find tickets (improving your homecourt advantage). While on the other hand, if your "Fab 5" isn't so fabulous and you start the season at 1-9, your homecourt advantage will most certainly drop.
Between seasons, home court advantage is reset based on traditional fan loyalty of the college, and the success of the team in the previous season.