Once you have an idea, do a little background research to learn more about how the history of the object and how it is made by searching encyclopedias, the library catalog, or the web. Sometimes the first result from a library catalog search will be a research starter, which is a short topical article with references. For example, search for "pencil" and look at the results.
Here are other library resources that give an overview of the object and a bibliography or recommended websites: