If your instructors make arrangements for library orientation for a specific course or assignment, appreciate the fact that they are trying to help you learn how to access the wealth of materials available in their specific fields of study. Know also that your reference librarians are specialists in helping you access sources. Just because a source is in the library, on the Internet, or has a Ph.D. behind its name does not mean it is credible or appropriate for your assignment. Evaluate your sources critically, weighing their content and purpose against the purpose of your research project. Academic research sources may be primary or secondary.
Primary sources provide information directly from a source.
Because these sources are primary, you can know that they reflect what the write chose to write at the time, but keep in mind that that the information in these sources may or may not be accurate and well-reasoned. The Declaration of Independence and Mein Kampf are primary sources, as are any of Thomas Jefferson's notes about the drafting process or any of Adolph Hitler's architectural sketches. Secondary sources provide information indirectly, through authors who have made judgments about the quality of the primary and secondary information they have used. You must evaluate how well-informed and unbiased these judgments were. A historian's recounting of research on the process of change in government or a psychologist's use of Freudian psychology to analyze Hitler's personality would be examples of secondary sources.