Usability.gov - "Your resource for desgning usable, useful, and accessible
web sites and user interfaces" 
    http://usability.gov/

From: Government Computer News - 04/16/2001
http://www.gcn.com

Checklist - National Institute on Aging and the National Library of Medicine
The goal of this Checklist is to provide researchbased guidelines for web
site design that, when implemented, will make web sites more accessible to
all adults.  
    http://www.nlm.nih.gov/pubs/checklist.pdf


Example sites:
Medline plus Health Information
    http://medlineplus.gov/

Interactive Age (online in 06/2001)
    http://www.nia.nih.gov

The Enabled Computer
    http://www.enabledcomputer.com/