To find basic background information about a discipline, basic textbooks can be helpful. You may already have one of these from taking a course. Or you can look in the UNO Library catalog for titles such as: introduction to (your subject).
Subject encyclopedias will also give background information on disciplines. The UNO Library has some in print, and some available electronically. For print and electronic reference sources, search in the UNO Library catalog. For an electronic collection of reference titles, use the database Literati by Credo.
There are several ways to find out the important journals in a subject area. Sometimes they will be mentioned in subject encyclopedias (some of these subject encyclopedias may be found in the database Literati by Credo). You can also do a search for a topic in a database devoted to your topic (if there is such a database) and see where many of the articles are published. Lastly, you can consult a source such as Journal Citation Reports (part of the Web of Science database) for journals which are most cited.