http://www.ducatimeccanica.com/
This site will point you in the right direction for a lot of things. Also, there is a bevelheads mailing list that has a lot of knowledgable people on it.
Info for subscribing to the list is on the ducati meccanica site.
There is also a forum at blocked-site.com:
http://www.blocked-site.com/~BB/phpBB2/index.php
But it isn't as busy as the bevelheads list.
EDIT: Oops, I guess Steve got on someone's nerves around here... you can find a link to a few places here:
http://www.teamyikes.com/bikelinks.html