Which citation style to use depends on the discipline of your course and professor for whom you are writing. The two most popular styles are MLA for humanities courses and APA for the sciences. Many social science courses may use the Chicago/Turabian style. When in doubt, ask your professor which style they prefer.
Each citation style has a handbook describing the details of writing citations for various types of resources. The library has at least one copy of each handbook on reserve or in the reference collection that can be located by searching the online catalog.
There also are many citation helpers on the internet. Remember, when you are using a citation builder you should always double check the format of the citation before including it in the final version of your paper - they may be machines but they are not always perfect!
Sometimes you need more than a quick citation builder. Besides just helping you format citations and bibliographies, citation management software allows you to organize and take notes on your sources in one place, as well as share references and collaborate on projects with colleagues.