Background Information gives you an introduction to a topic, issue, or person. It's what you're looking for when you look up "Aphasia" in an encyclopedia. Knowing a little bit about something you are researching helps you focus in on what's really interesting to you, as well as discern alternate search terms.
Feinberg Library has both in-print and online reference resources! Here are a few suggestions to get you started, use the call number at the end of each title to locate the resource in the library. Electronic resources are used by clicking on the e-link in the Feinberg catalog.
1. Kent, Raymond D. The MIT encyclopedia of communication disorders / 2004 Ref. RC423 .M56 2004
2. Nicolosi, Lucille. Terminology of communication disorders : speech-language-hearing /1996 Ref. RC423 .N52 1996
Books generally provide in-depth coverage on a subject, but because of the amount of time involved to write and publish, the information is not always up-to-the-minute.
Compared to books, journal articles tend to focus on a specific aspect of a topic and are less useful for general overviews or histories of a broad topic. If however, you search for a special type of article called a Review Article, you'll locate an overview on your topic.