filmshooting.com
a great site with perhaps the best forum out there for super8 users. Search the forum for a wealth of information.

cinematography.com
has forums for super8, 16mm, 35mm, processing, etc

8mmforum.film-tech.com/ubb/ultimatebb.php
as the name suggests, a forum for the 8mm user

www.kodak.com/global/en/service/faqs/faq2107.shtml
a Kodak page containing the super8 cartridge film speed notch chart

super8wiki.com/index.php/Main_Page
the super8 wiki is huge!

super8wiki.com/index.php/Category:Manufacturers
this link will take you directly to the super8 wiki's camera list

http://www.filmkorn.org/super8data/
The super 8 data base has technical info about a very wide range of super 8 equipment. Of particular use is the camera list which indicates which types of film each camera is suited for.