This can be a summary of others' research or an explanation of a process. There are different types of information. You probably will need a combination, but look over the categories below and decide where to focus your energies. You may have already looked at some general information sources in filling out the chart above, but if you didn't it often saves time in the long run to look at an encyclopedia article on your topic. Major ideas and facts will be given, and when you look at more specific sources later, you will have a better understanding of which ones are more significant.
Librarians know good sources of background material for topics, so ask.
There are so many sources of facts, it's easiest to ask the librarians for guidance in selecting useful ones. These sources are quickly updated and often focus on specific places and issues. Individual's opinions are often stressed, whereas other sources usually have a broader perspective. They are longer than the sources listed above, and they are usually written by experts. For background, the librarian shows you an article in the Encyclopedia of American Foreign Policy covering Mexico.