Thyca–Thyroid Cancer Survivors Association–A wonderful source of information about thyroid cancers. They have a forum, too!
Thry’vors–Thyroid Cancer Canada–another great source of information, even if you’re not Canadian! They also have online forums.
American Cancer Society’s Thyroid Cancer Pages–More good info. You can see their Overview or their Detailed Guide. Forums specific to Thyroid Cancer can be found here.
Thyroid Anatomy–This page has some interesting graphics showing the anatomy of the neck, including the thyroid