NOTE: You may use any audio editing software of your choice. Resources are provided for Garage Band but you are not limited to using this software.
What is it?
"GarageBand is an audio production software for use in Mac OS. This application is not really intended for professional musicians; instead, GarageBand is designed to help amateurs produce their own masterpieces easily.
"The recent version of GarageBand allows anyone to have a good quality internet radio or podcast. Some artworks can even be added to the podcast such as changing images per chapter or segment that serves as visual cues to the audience.
"Want to sound like a real disc jock[ey]? GarageBand also has a built-in Sound Enhancer maximizing and improving your vocal range and the sound of your voice. It can simulate a professional microphone that can give excellent sound for your Mac.
"Remote interview and conference recording is also possible with GarageBand 3. With the use of iChat, GarageBand automatically records whenever a participant speaks. It can also take a snapshot of the participant speaking when an iSight camera is used."
text from http://www.partnersinrhyme.com/contact/tutorials.php?sub=Garage%20Band&cat=Recording%20and%20Mixing%20Music&sno=57
Samples of using GarageBand in the classroom
Rod Blitvitch has his high school senior science students make audio recordings as part of their assignments in his class.
In Skowhegan, Maine, students researched local history and made podcasts that were combined into a historical walking tour of the community.
How do I use it?
Goochland County Public Schools in Virginia has a good information page on using GarageBand.
Apple Inc. has a collection of video tutorials on various aspects of GarageBand. Though the focus is on the music side, much of what they describe directly impacts any audio tracks you might make including voice and sound effects in addition to music.
The Educational Technology Clearinghouse has a collection of podcasting video tutorials on using GarageBand in the classroom.
Additional tools and resources
Apple Inc. has a variety of support resources including a question and answer forum for users, troubleshooting guides, and more how-to video tutorials.
Free clipart (34,000 pieces and growing) for students and teachers from Florida's Educational Technology Center (ETC). It may seem odd to mention clipart (purely visual) on a page about audio recording and editing, but you can put still images in the "cover art" section (where album covers show up on your MP3 player) and enhance your audio recording.
GarageBand graphic from http://www.glnd.k12.va.us/resources/gb/guitar.jpg