Bibliographic management tools enable you to store library sources in your own personal database and then incorporate the citations seamlessly into your research paper in whatever format your writing seminar requires. Within these tools you can take also notes on the books and articles you find and search those notes by keyword.
In particular, Zotero is a very powerful tool that you can download and use for free--download it here, and watch this 5 minute video which will get you up and running!
Also, here is a guide I created for using Zotero at Princeton.