I have always had (at least) one of these for any car I have ever owned.
Need help fixing your Honda Civic? Haynes has a wide selection of service and repair manuals to help you handle the work yourself.
haynes.com
Clymer is another company that publishes these, as well as the Honda (or whatever car-in-question)-brand book.
Of course, I began way before there was an interwebz, but it's still common practice for me. Even with the internet, I still find them to be valuable references.