Follow the instructions below to sign up. You'd go to https://www.addsearch.com/, create an account, have it crawl your site(s), and then pay them. You want the $25/month ($29 if paid monthly) plan and then add the 10,000 documents extra ($25) IF your site has more than 10,000 pages. Many of our customers sites do, BUT if you've got small sites the $25/month plan will work. But if you tell them you're a nonprofit, it's less.