Printed style guides are in the Citation Style Guide Collection by the reference desk.
Chicago (Reference Z253.U69 2003)
For humanities (e.g. literature, history, arts).
MLA (Reference LB2369 .G53 2003)
For languages (e.g. English, Spanish, German).
Scientific Style & Format (CSE) (Reference T11.S386 2006)
For biology & general sciences. Also known as the Council of Science Editors (CSE) and formerly as the Council of Biologist Editors (CBE).
Citing Internet Resources (Reference PN171.F56 L5 1996)
This guide fills in the gaps of other style guides when dealing with online resources. If your other styles guide doesn't mention how to cite an online source, try this.
Zotero is a free, open source browser app that collects, manages, cites, and shares your research sources. There is a browser extension that saves info and connects with the desktop Zotero (you need both desktop and browser extension). Additional info at:
Learn four common tools that will make citing resources much easier: the library catalog, library databases, Google Scholar, and Zotero. Additional info is available on the Why Cite Sources page.