here's the FAQ: http://about.bandamp.com/faqs.html

could do with an update though - since the site itself has been updated... Like.. the stars at the side of the "subject" text field can be used to rate songs or threads, which you should normally do. There are links to "how to" pages above the reply input form on every song page, to get you started reviewing/rating songs.

If someone replies to a thread started by you you will be notified via email.

If someone quotes a post made by you you will be notified via email too, however if this post has no subject there will be no link to the post available in that mail.

All in all this site navigates pretty much like a forum, for that is what it is: a forum.
Not just any forum though..

it's BandAMP!!!