One source for financial ratios by industry is the RMA Annual Statement Studies Financial Ratio Benchmarks. RMA is the acronym for Risk Management Association and formerly for Robert Morris Associates. Your banker and many larger libraries subscribe to this publication. It contains the financial ratios for 740 industries based on the financial statements of more than 265,000 small and mid-sized companies.
Another source for your industry's financial ratios is your industry's trade association, if it collects financial information from its members.
In addition to comparing your company's financial ratios to its industry, you will want to compare your company's financial ratios to its own past and future financial ratios. Spotting a trend early can be very beneficial.