A good way to include some supporting information from white papers and reports is to photocopy specific pages and highlight relevant text. That way, people don't have to wade through endless verbiage to understand what matters. Magazine articles make great handout materials because they are already pre-packaged and ready for referral. Also, make sure you distribute good copies. If you really want to go all out and you plan to distribute more than a hundred copies of an article, consider ordering professional reprints from the publisher.
Presenters often use case studies to illustrate aspects of their message.
But in researching case studies, we often dig up more material than we can possibly use. Including contact information is also a good idea, especially if there is a likelihood that people in your audience might want further information firsthand. These days, a list of useful Web sites related to the topic you are addressing is a valuable handout component. If only one or two specific Web sites apply, consider printing out home pages to give audience members an idea of what the site looks like. If your own organization has a Web site, don't overlook the opportunity to direct people there.