Reference books are encyclopedias, directories, and other similar books designed for east access to information. They are handy and informative, so use them as a starting point for your research. It's a quick way to find out important names and events, get ideas for keywords to use in online searching, and get an overview of your subject.
Most of the print reference books listed below are located on the first floor just above the Pit. Dance books generally are under the numbers REF GV1580-1799.4. Some are in the Ref Stacks on the third floor, however; just look at the call number if you aren't sure. Be sure to ask the person at the desk if you have any difficulty finding these books!
As you start your research, what information do you already know about your topic? What information would be useful to know? Encyclopedias and dictionaries are good sources to consult when you are at the beginning of your research and you are compiling the basics about your topic. Also, search the catalog for books on your topic that can provide a detailed history of it.