Q:

Character Limit

How do I setup a character limit in a specific column to limit the amount of characters? 

A:

In your list/library settings.  Go to the column section and find the field you want to limit.  Click on the field to go to its settings.  There is an option for Maximum number of characters.  By default this will be 255 for a Single line of Text field.  You can change it to less than that here.

