Part of researching at the advanced level means discovering what scholars have already said or done on a certain topic. You are using existing knowledge to (possibly) create new knowledge on your specific research question. Or you are at least putting your two cents in about a subject. But you can't just take someone else's project, ideas or results without giving credit to them. This is plagiarism, which is a serious offense. (There should be a statement about Academic Integrity in the syllabus of each course you take. Here is a link to the University's policy: http://www.sacredheart.edu/officesservices/registrar/academicintegritypolicy/ )
I think it is worth making clear that: Yes, your citations go at the end of your paper in the form of a bibliography, works cited or references page. But, as you are writing you should be citing from your sources throughout your paper. You can't write your paper, and then attach a list of websites, book titles and journal articles without incorporating them all and call it good. Sorry, not sorry.
Myth: Citations can be saved for the end of the project.
Ask anyone who has done a research paper, and I guarantee they will have a story about how they finished writing the paper but then had to spend a lot of time formatting their citations and reference lists.
It would make your life a million times easier if you start to keep track of your citations/sources from the beginning of your research project. And thankfully, we now live in a world where there are websites and software that can help you do just this.
The box below has a video about Zotero, which is a citation management tool. Most librarians (including this one) think this is one of the best tools to use in research. If you are not really interested in investing the time there, Zotero now has a quick citation tool called ZoteroBib. You can use it for any citation style, and all you have to do is put in the URL, ISBN, DOI, PMID, or title and it format a citation for you. As usual, double-check that the citation is correct by using one of our Citation Quick Guides.
Here are some helpful guides to formatting using APA citation style.