GarageBand comes with a wide array of jingles and sound effects to make your podcast pop. This tutorial will show you how to use them in your podcast, and how to do fades and adjust audio levels of different clip segments.
Add an Intro, Outro or Sound Effects
Click the Loop icon in the upper right hand corner to open the Loop Browser and then the column icon to use the column browser
To adjust the overall volume of a clip, drag the slider next to the track adjustments to the left or right. Be careful not to increase the volume to high so that it will distort.
To fade your sound effects and music in and out you will use what is called automation.
First navigate up to the menu bar at the top of the screen, and click on the Mix header. Within this list, select Show Automation.