"We are not evil" is the site's by-line. Check out why they want you to podcast their music! This is a great stop on your music search.

They have terms for no-cost podcast license for both non-commercial and commercial podcasts.

Visit Magnatune.com

From the site:

You are allowed to: download, copy, share, trade, distribute, and publicly perform (e.g. webcast) any of the files available in the feeds listed in our highly moderated database. All our feeds have agreed to the Music Sharing License available through Creative Commons.

Visit audiofeeds.org

Part of the iLife package for Macintosh OSX, GarageBand is an easy-to-use software studio for music and voice. Record, edit, and save as MP3 files ready for podcast listeners.

ALSO! GarageBand can compose music for you in different genres such as light rock, jazz, blues, dance, house, hip-hop, and more. You can use a library of "loops" for parts and melodies, alter them, or compose your own. You can use any music thusly composed for anything you wish, royalty free, forever. This can fit the bill nicely for background or intro/outro music.

Apple's GarageBand Product Page

Apple also has online tutorial on using GarageBand to make Podcasts, too!