1. General: The Copper Development Association has a top-notch website with tons of useful information.
2. Chemical Compatibility of copper: "1.3. Architectural Considerations - Weathering, Corrosion, Staining, Substrate, Solder, Sealants" is a great page on the Copper Development Association website. Well-written and very informative.
4. Safety: See this Material Safety Data Sheet for health and safety information about copper at the Revere Copper Products website. This is only an example and other products and brands may be different.
5. Technical: Architectural details of various styles of copper roof systems can be accessed from this page at the Copper Development Association's website. Click on the type of system you're interested in at the top of the page. The drawings are done well and give you an idea of what is going on in a copper roof system.