The best resource we have to research industry information is the IBISWorld database. Search for any industry such as computer manufacturing, construction or telecommunications and you will get a report with specifics about the entire industry.
We have several additional resources for locating industry information:
In the Nexis Uni research database, ratios for any group of publicly traded companies can be compared by searching in the Company Dossier portion of the site.
Key in ticker symbols or names for as many of those companies as you want to compare.
After entering all the tickers for your set of companies, you will retrieve a Company Financial Comparison giving balance sheet and income statement items, followed by the header Ratio Analysis. Here you'll find a long list of ratios.
NOTE: This will work best with companies who are direct competitors in the industry (i.e. they have the same primary NAICS code that your company has). Comparing two companies with diversified operations may be of limited value. For example, Apple and Motorola are competing for mobile phone business; but each one competes in a good many other product markets as well. So ratios for the whole company do not give a very clear or complete picture of how they fare in the cell phone market.