Einstein and Leisureguy's (Michael Han) grandson. Posted March 23, 2007.
The CD entitled "Historical Modules for the Teaching and Learning of Mathematics" (Katz and Michalowicz, 2004) contains many modules of historical content. It is listed in the library catalog and it is also available for you to look at in my office hours. The library catalog can contain many useful references. Historical References Library books office contain a wealth of historical information.
Websites such as the MacTutor History of Mathematics archive (O'Connor and Robertson, 2005) provide an extensive collection of articles on particular people and topics. The Earliest Known Uses of Some of the Words of Mathematics (Miller, J, 2008) can provide history on the development as well as the first published appearance of terms.
Some topic searches may yield many unrelated pages or be too general a search - for example, similarity means many different things in real-life. A modified search such as the history of "similar triangles" can be more productive and it leads to a mathematics history journal article Proportionality in Similar Triangles: A Cross-Cultural Comparison
As always, I am happy to help.