Secondary sources:
We have a couple of online sources that provide ratios, but they are limited in the number of companies they follow and/or the type of ratios they provide. However, if you are in those databases already, it may be simple to pull the ratios directly from them.
When you do an industry search, and display the results, ratios are listed under the tab to the far right, "Key Statistics." Please provide feedback on whether this database was useful to you or not..IBISWorld is now including RMA ratios under the data tab for an industry report.
These books provide background on understanding and using ratio analysis.
The full list of books about ratio analysis and financial statements. Below are the "classics" and highlighted materials:
Financial Statement Analysis by 
Financial Ratios by 
Business Ratios and Formulas by 
How to Read a Financial Report, 9th ed. by 
Handbook of Business and Financial Ratios by 
Key Management Ratios by 
Total Management by Ratios by 
Understanding and Analyzing Financial Statements by 
Business Valuation: Theory & Practice by 
