How do I move a .mp3 file I created in my music software to iTunes?

My music software now has .mp3 creation capabilities, with ID tags. I am trying to insert one file as a test (and the ID tags are filled in). In my PC running Windows 7, I navigated to Music\iTunes\iTunes music\[new folder] and place the .mp3 file there. But when I open iTunes, my file does not appear in the list. I've clicked on all the subcategories to alpha them, but no luck. How do I install this? I need to know because I am going to offer .mp3 files with a book I've written, which is being published now.

Thank you!