Most recent volumes are held at the Floor 2 Reference Desk. Older volumes are either in the Floor 2 Reference stacks, or on Floor 4 stacks -- all filed under the same call numbers as these.
Almanac of Business & Industrial Financial Ratios
Industry Norms & Key Business Ratios by 
RMA Annual Statement Studies by 
Business Ratios and Formulas by 
Dictionary of Financial Formulas and Ratios by 
Encyclopedia of Financial Models (eBook) by 
Financial Ratios by 
Manager's Pocket Calculator by Morningstar describes financial statements as "windows into a company's performance and health." They certainly are that, and so much more. As noted in the Searching EDGAR guide, financial statements as found in a company's 10-Q and 10-K reports yield a wealth of data about a company. This data can be plugged into standard formulas, thus producing insights that can uncover otherwise hidden realities about the financial health of the company. These formulas are known as business / financial ratios.
According to the Oxford Handbook of International Financial Terms, ratio analysis is "a collective term for analytical methods based on an organization's financial statements and used as indicators of financial position." The Handbook notes that ratio analysis also can be conducted on non-profit organizations.
Morningstar notes that some ratios are useful in and of themselves, but most are useless if not put into some kind of context (compared against themselves over time; compared against other like companies in an industry, etc.). [NOTE: In order to understand how to find industry benchmarks, you will need to understand the SIC / NAICS system].
You can find ratios going back 5 years or more for individual companies by going into Standard & Poor's NetAdvantage database (link below).
Once you are in the database, search for your company by name or ticker symbol in the "Simple Search" box. After the results for your company search are delivered, look in the left-hand frame where you will see a link that reads "Compustat Excel Analytics." Click on that link, and then set the drop-down menu (center of page) for "Annual Ratio Report." You will then be able to download an Excel spreadsheet with several or more years of business ratios for your company.
There is also an "Annual Comparative Report" that provides ratios for the top competitors of your company.
[NOTE: you will not be able to download any reports if your pop-up blocker is enabled. You may be prompted to temporarily disable your pop-up blocker before downloading each report].
ALSO: In the IBISWorld Database, each industry profile has a "Key Statistics" section that lists several industry ratios going back about 5 years, and with forecasts for 3 years into the future.
Though opinions will vary, in general, typical financial ratios can be classified into the following basic categories (some sample ratios are provided):
Reading Financial Reports for Dummies (eBook) by 
