When you register for Animoto, use any e-mail address you'd
like but be sure to go to the http://animoto.com/education page and follow
their steps. The education account allows you to make unlimited length
movies (not just 30 seconds) and also gives you 50 "student" access accounts
(codes students put in when they make their accounts that allow them
180 days of unlimited movie making).
Once you've installed audacity and start playing around
with sound, it will help if you have the LAME encoder (this will allow
you to export in MP3 format). The best link I've found is at: http://lame1.buanzo.com.ar/.
The page is not very friendly, but it's the first link under For Audacity
on Windows: (following FREE MUSIC).