We have many books on this topic in the library; do a keyword search for your topic.  As well, you can look at our online resources, including SIRS Researcher, Britannica 2000, and Worldbook 2000.  Finally, the old SIRS volumes in the Reference Room have a lot of articles particular to your study.

The first place to check on the web for information would be at Yahoo!  This search site is organized into the specific topics you are looking for, and each of the pages has been reviewed for relevance and validity.  Many of the following links are directly from a simple search on Yahoo!