As a photographer with a new DSLR, you might be trying your hand at video production. Most people completely overlook audio and they shouldn't. If a video sounds cheap then in most people's minds, it is cheap. If you don't have enough money to afford fancy lav mics, don't worry, you can record clean audio with a number of devices that you may already own.
Over 300 free loops and sound samples for you to download, Drum loops, Acid loops and Samples, Hip Hop Loops, Hip hop Samples, Bass, Guitar, Synth and more
If you are a mini-plan Ning user frustrated that you can't post video and audio, Edmodo may be the answer. It's actually a lot like PB Works. Students won't be able to customize their own page but you can add multiple files to an assignment post.