I have a site that uses custom database tables to manage info that is inserted by a process completely independent from Wordpress. The data from the table is used in the Wordpress site but it is not manageable through the Admin interface.
I want to make it manageable via the admin backend. What is the basic process for this? In my mind I need to create a link in the Admin sidebar to "Manage Custom Data" and that link opens up a page that permits basic CRUD management of the various rows in the table.
This would be effortlessly simply in vanilla code but I am not familiar with such custom aspects of modifying Wordpress so I am just looking for pointing in the right direction. Give me the big picture, in other words.