An important part of historical research is the use of primary and secondary sources.
What can I find in the following primary sources?
Diaries, journals, speeches, interviews, letters, memos, manuscripts and other papers in which individuals describe events in which they were participants or observers.
Memoirs and autobiographies. These are generally less reliable since they are usually written long after events occurred and may be distorted by bias, dimming memory or the revised perspective that may come with hindsight. On the other hand, they are sometimes the only source for certain information.
Records of organizations and agencies of government. The minutes, reports correspondence, etc. of an organization or agency serve as an ongoing record of the activity and thinking of that organization or agency. Many kinds of records (births, deaths, marriages; permits and licenses issued; census data; etc.) document conditions in the society.
Published materials (books, magazine and journal articles, newspaper articles) written at the time about a particular event. While these are sometimes accounts by participants, in most cases they are written by journalists or other observers. The important thing is to distinguish between material written at the time of an event as a kind of report, and material written much later, as historical analysis.
Photographs, audio recordings and moving pictures or video recordings, documenting what happened.
Artifacts of all kinds: physical objects, buildings, furniture, tools, appliances and household items, clothing, toys.
Research reports in the sciences and social sciences. Especially for recent social history, the best evidence of broad developments in society is often in the form of social science surveys or research studies. This research is generally reported in book form, government reports or most commonly in articles published in scholarly journals.