Each School Year must  be specifically and manually created on the Setup→School Years→List School Years screen:

Adding a School Year to the System

1. Go to the Setup→School Years→List School Years screen.
2. Click the Add School Year button.  This brings up a "new School Year" dialog:
    
3. Fill in the School Year.  
4. If you are missing any years, you can click the button to add them

These is no limit to how early you can create a School Year, or how many school years you can add.

Once you have added a School Year to the system it can be used to add year-specific information (e.g. Salary Guides) for the specified School Year.