Somewhere around iTunes 9, Apple created a new organization for the iTunes folders, basically to invent the "iTunes Media" folder. This was to provide a better structure for people who were starting to acquire lots of things in iTunes besides music.
Depending what decisions people made at the time, they may or may not have upgraded their existing library.
Any podcasts that one user downloads will go into the Podcasts folder within the iTunes Media folder (as designated in Edit > Preferences > Advanced) for the user who does the download. That is independent of anything the other user does.
I have my library setup so that both my girlfriend and I can use the same library without any duplication of music or separate media folder. The library shows both of our playlists & apps. If I add anything whether it's a song, movie, video or app it updates the folder and when she logs in she sees the same exact thing I do. Is that what you're trying to accomplish?