Books4Cars.com contains thousands of service manuals for a variety of makes and models. This website charges fees to download manuals, typically ranging from $10 to $20, as of 2015. The Old Car Manual Project contains a number of free downloads, though their selection is not nearly as extensive as Books4Cars.com.
The website FossilCars.com is a valuable aggregate tool that makes finding service manuals for older cars easier. The website of a car's manufacturer sometimes offers information pertaining to its older models as well. Websites such Amazon and eBay sell physical copies of manuals for older cars. However, Books4Cars.com is the most efficient and thorough source for older automobile service manuals.