I have built a cms codebase over the years that allows clients to administer areas of their sites. I'm slowly moving to wordpress for many sites, but one topic which is stopping me is how to customize the backend to add management of custom data.
Say I have a client who makes wood stoves. They maintain a list of dealers and installers, and want to save details about these companies, and then display them in some fashion on a site page. I can build a secure login section with the forms and functions to allow them to do so.
My question is whether I can integrate this into the wordpress admin system, or whether I have to give them a separate admin url? If it's possible to integrate, could someone outline the approach to take - I can work out the details, but need to know where to start.