This page explains how to buy yourself a domain name from a registrar, and how to manage it at HCoop.
Find a registrar
If you want to manage a domain with DomTool, you must first buy a domain from a domain registrar. Search for "domain registrar" via your search engine of choice to see several of the available options.
DNS options
If your registrar provides a web interface for managing the DNS records of your domain (some examples of registrars that do this are [http://godaddy.com/] and [http://gandi.net/]), then you can either use their web interface to fully manage your DNS, or you can use DomTool.
Managing DNS using the registrar's website
Using Domtool to manage DNS
Registrar pitfalls
Be sure that you provide a valid contact email address. If the email address you give your registrar is invalid, you might miss the reminder email when your registration is about to expire.
Don't let that domain lapse. Be careful not to let your domain lapse. Otherwise, unscrupulous people may buy it and then try to sell it back to you at a profit.
Lock your domain once it is set up. All registrars should permit you to "lock" your domain. The reason you want to do this is because you can lose your domain by not answering an email from ICANN within 5 days if your domain is not locked. Do this after setting up your nameserver information. You can lock and unlock your domain at any time, though the change may not be instantaneous.