Chaucer information and etexts
http://www.librarius.com/duchessfs.htm
Librarius is a site about Chaucer that includes etexts of Chaucer's poetry, including hypertext links to Middle English words. Not all obscure words are glossed, but this is an excellent resource for quick understanding of the sense of a line.
Chaucer
http://www.online-literature.com/chaucer/
Information on Chaucer and his works by Online Literature.
The Chaucer Quiz
http://historymedren.about.com/library/weekly/aa082799.htm
A quiz about Chaucer's life and works on About.com.
Essays and Articles on Chaucer
http://www.luminarium.org/medlit/chaucessays.htm
Essays and articles, some by students and some at a high level, on Chaucer's works. Many pieces are very useful for in-depth research. Some bibliographic information is also available. Luminarium's sources on medieval literature and on Chaucer are extensive.
Geoffrey Chaucer
http://www.encyclopedia.com/doc/1E1-Chaucer.html
A good introduction to Chaucer at Encyclopedia.com, including some pertinent links to journal, magazine, and newspaper articles.
Middle English Glossary
http://www.librarius.com/gy.htm
The online Middle English Glossary on Librarius.com. You can use your Internet browser's "find" function to locate a particular word in the list.