Here are some resources to locate resources for the elderly.
When visiting a website that asks for sensitive information such as your address, medical conditions, etc., make sure it's a credible site! That means doing research about the site. Are there any reviews of the service? Has any newspaper written about the service? Did you check Wikipedia - if so beware! Many companies edit their own Wikipedia entries to try to make them look like legitimate services (this is against Wikipedia's terms of service but there have been recent violations).
Make sure that any site where you're providing sensitive data (payment information, health information, social security number, etc) is using a secure connection. Any site that's not encrypted is at risk of compromising whatever information you provide (including passwords, emails, etc).You can tell if a website is using a secure connection if you see a lock icon in the URL bar or if the URL starts with https (see example below).