1. List the domains for sale on domain marketplaces.
You can sign up at Sedo.com and Afternic.com in order to list your domains for sale on their site. People can then find your domains and submit offers through their system.
2. List the domains for sale on domain forums.
DNForum.com, DomainState.com, NamePros.com
3. Press Releases
Release a press statement including your domains and stating that they are for sale. If the domains are good some buyers might get in touch with you.
4. Contact potential buyers directly
This is the best way for selling high-priced domains, in my experience. However, this requires that you do some research to find buyers and you should have some contacts in the industry.
5. Domain brokers
You can contract a domain broker to actively promote your domains. Most brokers only sell better-quality domains though, because brokering domains is a business that costs the broker both time and money.
6. Park the domains and put a "for sale" link on the parking pages
7. List a "This domain might be for sale" note in the domains' whois information
8. Buy advertising spaces to promote your domains for sale
9. Be creative. There are many ways to sell domains.
Regarding those free domain appraisal services, I wouldn't use them. If you want a free appraisal, post the domain for sale on this forum.
Good luck!
