I'm sure someone out there knows a place that sells film cheaper, but here's a link to Spectra. They'll sell you a whole package deal in for Super 8 where they'll send you some film. You use the film up and then send it back to them for processing and telecining. You can have them send the footage back on a variety of different media from just film to minidv, betaSP, or even on an external hard drive(you have to supply the drive).
I'm planning a shoot in the near future and unless I find someplace better/cheaper I'll prolly use them and have them send me the footage on a hard drive.
http://www.spectrafilmandvideo.com/Film.html
You should decide ahead of time what exactly you'll be filming, and in what conditions you'll be filming....such as daylight, indoors, night time, etc...then call spectra and have them help you decide what kind of film to use for each situation, and what setting should be what on your camera for using those films.
Of course it never hurts to find out how to set all the stuff yourself, as an informed filmmaker is a powerful filmmaker. If you want to make some KILLER films I'd suggest grabbing an vintage/antique exposure meter off ebay($20 or so, and make sure it comes with it's original instructions), some filters(they're 43mm, but I'm unsure of the fit from different sets, so I'd visit a local camera shop to have them test out some various 43mm's for fit), and grad a few books on making films. I havn't read it yet, but skimming through it it appears that "Cinematography by Kris Malkiewicz" covers all the bases.....there's alot of crappy books on filmmaking out there that just end up being "fun". try to avoid these and grab technical books so you know what your doing. In this post :
http://www.indietalk.com/showthread.php?t=13518
I list a number of books on the subject, and in fact the book "The Camera Assistants Manual by David E. Elkins" has an excellent list of books to search out.
Good luck with Super8!! It's a GREAT looking format! Here's a link to something shot on Super8 :
http://www.windowseatpictures.com/06vtc/intro.html