When you tap Music from the main screen of the iPod Touch, you'll see five icons on the bottom of the screen. The default icons are Playlists, Artists, Songs, Albums and More. If you like, you can customize this menu pretty easily to add other options such as Podcasts.

Just tap "Edit" in the top-left part of the screen and you'll see nine more icons. Pick one of the additional icons, such as Podcasts, and drag it on to the existing icon that you want to replace. When you do this, they'll swap places. You can also re-order the icons that are shown. Just drag them around and they’ll swap places. Once you have icons set to your liking, tap "Done" and your changes will be saved.