C#, Podcasthandler. Connecting two objects to one XML

I´m trying to create a "podcasthandler". The handler is supposed to give the user a search function in which the user can select a certain category and get every podcast which belongs to that category.The user also has the possibility to create a new category.

What I have done so far is that I have 2 seperate XML documents, one containing podcasts objects and one containing category objects. My main issue is that I´m not sure how to connect a certain podcast to a category. Should I create a single XML where every entry have a podcast URL and a category assigned to every entry? And how do I do that? I´m pretty new to C# so looking for the easiest way possible to do this.

I´m grateful for every tip!