One of the best assistances available to get you started on your citations is often the very resource you're looking for your articles and books in.
Look for a link to Cite or Citation or Reference to get a citation you can copy/paste into your Works Cited or References page.
Don't forget, however, that you must check these citations over for accuracy. Ultimately, you are responsible if the citation is incorrect, so be sure to double-check anything that you copy/paste from a resource.
Citation Builder will let you type information into boxes and will return a citation in APA, MLA or other formats.
You can get more citation assistance at the Library's Cite Sources page, which includes many other citation builders (you fill in box and get back a citation) and general assistance information.