Consult the Library's Writing and Citing resources to learn more about how to use a citation management database to track, build, edit and produce references and bibliographies. There are many different and free citation management tools available. A more extensive list may be found here.
Lots of new quick citation management tools including Citation Machine, bibme, APA Referencing Generator, EasyBib for a variety of most often used formats.
The most comprehensive and inclusive quick citation database with many different citation styles that allows for the inserting of DOIs, ISBNs and other numbers is ZoteroBib.