An introduction to mediaeval dance is available from the ORB's mediaeval dance page. Images of actual mediaeval dance and dancers are available at the Medieval Dance Picture Collection; the page is mostly in German, with some English-language text.
A site with guidelines and examples for reconstructing 15th to 17th dance is Kenneth J. Reed's Dance of the Ages.
Andrew Draskoy's Renaissance Dance Home Page offers information and archives
from the RenDance discussion list, and links to on-line
resources for students of Renaissance dance, including transcriptions from manuscript sources.
Also focussing on Renaissnce Music and Dance are
The SCA Renaissance Dance Homepage and
Del's Dance Book, with a focus on the reconstruction and teaching of Renaissance dance (the site also provides 2 annotated bibliographies).
Two sites sponsored by dance groups are the Early Dance Consort (see the "Links and Useful Contacts" section) and the
Dolmetsch Historical Dance Society.
Mainly Morris Dancing provides variety of information about the Morris (including modern Morris groups). Of particular interest are the section containing the Morris FAQ's and the section containing History links.