Graham Martin , Aug 11, 2010; 12:09 a.m.
In the search bar type in Mamiya C3, and it will bring up several postings. That would be one good place to start. So far as film it uses there are two commin types. 120 and 220. The 120 records fewer images than the 220, but it is relatively easier to find that 220.
You may also want to google for an instruction manual. You can find them here: http://www.butkus.org/chinon/mamiya/mamiya_c3/mamiya_c3.htm