How much information you will need depends on the type or nature of your assignment. Read your instructor's directions carefully to get an idea of the assignment. Is it a short essay/summary/presentation or is it a ten page research paper/ or long essay/critique/project?
If the assignment is short you may need to read just one or two brief encyclopedia articles or factual essays or topic overviews to find enough information. If the assignment is research oriented, you will need to spend time finding more comprehensive and detailed information from varied sources to support your arguments.
Information comes to us from many sources - books, magazines, journals, newspapers, radio, television, internet, multimedia sources, etc.
What kind(s) of information do you need? This depends on the nature of your assignment.
Do you need books? If your paper does not require very current information or if it contains historical information, you could use books. You can also use books or encyclopedia articles to find background information on your topic.
Do you need periodical articles? If you need very recent or current information you will need to find periodical articles on your topic. If you are writing a research paper you will need scholarly sources such as peer-reviewed articles. Quite often professors will require you to find scholarly or research articles on your topic rather than articles from popular magazines.
Are you allowed to use magazine and newspaper articles that are not scholarly but may contain valid information? If you are writing a paper on puppy mills, for instance, the chances are that there are no scholarly articles on that topic so you will have to rely on newspaper and magazine articles.
Do you need primary sources on your topic? For some assignments it is enough if you consult secondary sources such as textbooks, encyclopedias, commentaries, periodical articles, etc. These sources interpret and analyze primary sources. Other assignments may require primary sources which are original documents such as diaries, letters, interviews, speeches, autobiographies, manuscripts, creative works such as poems, music, art, etc.
Can you use web sites? You may use web sites if your professor says it is okay to do so. Certain kinds of information such as information on government agencies, federal documents, company reports, etc. may be available only through web sites.
Do you need audio files or video clips? This, again, depends on the assignment and your instructor.