(You might be looking for Smoke Vents.)
3. Technical: For an in-depth introductory technical article about skylights, see this page at the Whole Building Design Guide site, which is maintained by the National Institute of Building Sciences. It's a very good page.
4. Technical: "Performance of Tubular Daylighting Devices" is a detailed article from 2014 available on the National Research Council Canada website. Well worth reading if you're interested in or considering these energy-saving devices.
5. Technical: See this Product Data Sheet for the technical characteristics of prefabricated skylights at the Bristolite website. This is only an example and other products and brands may be different.
6. Technical: Another article worth taking a look at is "Daylighting" on the Whole Building Design Guide site. The article covers much more than skylights, but it helps you understand skylights better by putting them into a broader context.
7. Manufacturers: See here for a list of skylight manufacturers.