I am assuming that you are using a central database.
I see that you would need to create a
site table (used to store the sites that will use the database)
Checklist Template (list of things to check off)
Checklist Completed table (a join table that links the site with the completed items from the template table)
Lobster Thermidor aux crevettes with a Mornay sauce, served in a Provençale manner with shallots and aubergines, garnished with truffle pate, brandy and a fried egg on top and Spam - Monty Python Spam Sketch