Yes, Audacity doesn't support batch processing, and you'd have to do run each song through manually. The LAME plugin is what actually allows Audacity, and many other apps to process MP3.
If you're looking for something really simple, and don't feel like having the options of Audacity, try LameDropXpd:
LameDropIt's really small
(380kb), doesn't need installed (creates an ".ini"), and has simple drag and drop processing. Just double-click to run it, and then right click on the window to choose your options.