Domain name tools
The first thing you need to do when you have an idea for a domain name for your site is check to see if its available. There are many places to do this on the internet. I’ve used godaddy.com, namebargain.com and register.com but there are many others. If you go to any of those sites you can enter domain names and check to see if they are available. Often they will also suggest similar names in case yours is already registered. You most likely will have to try this a bunch of times before finding one that you like and that’s available but start there and play around by trying different combinations until you find one that is available.
Sometimes you find a name that is registered that is not being used. You can try to find the owner by using the WHOIS database that keeps track of who owns each domain. Go to this link and enter you domain name and it will tell you the contact information of the person who owns any domain on the web. Many people use private registration so their personal information is hidden but there will always be a contact email address that you can send a note to if you are interested in contacting the owner.
http://www.networksolutions.com/whois/index.jsp
If you want to purchase a domain from someone you will have to transfer ownership. This can be a multi-step process but any domain registrar (godaddy, register.com, yahoo!, namebargain.com, etc.) will all offer these tools.
When you’ve found a domain you like that is available, create an account at any of the hundreds of domain registrars and you can purchase the domain on the spot. Most domains are about $10 per year. You can add other services such as private registration or parking pages but to simply take ownership of a domain you should not pay much more than $10.