Most of the citations you will see in databases, web services, etc., are produced authomatically using a computer algorithm. That means that if the data is incorrect, the resulting citation is incorrect. You have the final responsibility of checking that the citation is fully correct using the guidelines provided by your professor (or publisher).
Several websites have forms where you can fill in the needed information and get a formatted citation to cut and paste into your documents, like Zotero Bib -- the default settings include APA, MLA, Chicago, and Turabian, but there are over 9,000 styles avaialble. Citations are stored in your browser, no account needed.
These services also let you set up a personal account, but aren't specifically supported by the library.
For large or long term projects, it's often useful to save and organize citations, as well as cite them in a specific paper. Endnote Web, the online version of the popular, fee-based software, is free for anyone, though students, staffs, and faculty who sign up on campus get some extra features. Mendeley is free for anyone to install on their own computer, can be used offline, and is also more advanced. Zotero, another advanced tool, works best on your own computer, and lets you import directly from results lists. All have plugins for MS Word--the Endnote Web plugins are installed on the campus lab computers.
You can also get a personal subscription to Refworks, NoodleTools, or a personal copy of the EndNote software, which includes EndNote Web.