LDA
Lyme Disease Association, Inc.
Lots of excellent information on this site.

LDF
Lyme Disease Foundation
More excellent information and photos relating to Lyme and other tick-borne diseases.

Art Doherty's Lyme Links Page
An incredible resource. If you have a question about anything relating to Lyme disease, you'll find it in this comprehensive list of articles.

IGeneX
Lab specializing in testing for Lyme disease and other tick-borne diseases. Lots of good information, too.

Lyme Disease Network
An online community bulletin board that provides lots of help and support for those affected by Lyme disease.

CALDA
California Lyme Disease Association
Informative articles for both Lyme patients and physicians.