2. Technical: "Guidelines for Ventilating Attics and Cathedral Ceilings to Avoid Icings at Their Eaves" is a very technical article (lots of math and graphs) available on the website of the US Army Corps of Engineers Engineer Research and Development Center.
3. Technical: The principles of natural ventilation (as opposed to fan-driven ventilation) are presented well in this article at the Whole Building Design Guide site, which is maintained by the National Institute of Building Sciences.
6. Manufacturers: You can find ventilation product manufacturers here.