There are a good many bibliographical resources on the web. For the student of Chaucer the most important are those listed, with helpful descriptions, on the bibliographical section of The Chaucer Metapage. Among the most useful are:

    The Essential Chaucer
    (A selective, annotated bibliography of Chaucer studies by Mark Allen and John H. Fisher).

    Mark Allen The SAC Online Bibliography
    (Maintained by Mark Allen; fully annotated and searchable).

The above bibliographies treat only Chaucer. The thirty year bibliography by Derek Pearsall provides an often very useful supplement, since it covers the whole field of Middle English literature.

Another source of useful bibliographies are the various Chaucer pages created by teachers throughout the country; the best and most reliable are those listed, with helpful annotations, on The Chaucer Metapage: see the pages by Edwin Duncan, Alan Baragona, Michael Hanly, Anniina Jokinen, Dan Kline, and Jane Zatta.

A number of important critical studies are available on the site you are now reading; most are listed on the pages of the particular tales that they discuss. Or you can use the site index to search for them by author, title, or relevant work (a search for "critical study" will find them all).