The first section I visited was reference, which offers everything from demographics (Sourcebook of ZIP Code Demographics from Caci Marketing Systems Group, Rand McNally Commercial Atlas & Marketing Guide,or The Lifestyle Market Analyst from Standard Rate and Data Service) to industry trends (McGraw-Hill's U.S. Industry and Trade Outlook or Standard and Poor's Industry Surveys). Other topics include import-export, information on other businesses, legal and marketing, to name just a few. (See "Book Smarts" for more specific titles.) When you visit the business reference section, be sure to nose around. In the Newport Beach Public Library, large-volume sets like the Thomas Register of American Manufacturers are placed on tables for easier use, and many high-security items and loose-leaf books are behind the reference-desk counter.
Adjacent to this reference section, I found the business periodicals. Most public libraries have The Wall Street Journal--both current issues and past years--in their collection or on microfilm, as well as major newspapers like TheNew York Times or Los Angeles Times, depending on your area. Also look for local business publications to check out local industries and companies.