Namecheap — This company provides .com domains for $10.69 (plus 18 cents) per year ($9.69 if you transfer from other registrars). Along with your domain, you get free email forwarding, free web redirection (where anyone going to your domain is automatically directed to another address of your choice), free domain name parking, etc. For the first year (or at least, at the time I checked their prices), you can also have their WhoisGuard (where your particulars are masked from public view) for free. They have a wide variety of domain name extensions available, including .net, .org, .biz, .info, .us, .co.uk, .co, .de, etc. You can use either a credit card or PayPal for your purchases.
Before you sign up for Web hosting and start building a website, you need to buy the domain name where visitors will find your site. Hundreds of different registrars sell domains, so first and foremost, know that domain names work the same no matter which registrar you use. You don't need to buy your domain from the same company that will host your site. Aside from picking a registrar -- and, of course, your site's name -- you also need to pick a top-level domain like .com or .org.
Anyone can buy a domain name. To do so, you visit a domain name registrar, such as GoDaddy or Namecheap, key in the domain you want to buy, and pay a fee. You can't buy just any domain, of course—only one that isn't already registered by another person or business and that bears a valid domain suffix. In general, you'll want to buy something that is catchy and short so that it's both easy for people to remember, and easy for them to type in—like "PCMag," for example. That good search engine optimization (SEO) and it's also common sense. You might also want to do some research on key terms for your business. If you can get a good one into your site's name, that's all the better, from an SEO perspective.
Avoid having numbers in your domain name. People can get confused about whether the numbers is a digit (3) or a word (three). If you want a number in your domain name because there’s a number in your company name, buy both versions (digit and word) and redirect one to the other. Be especially wary about using the number “0” in a domain name as people may see it as the letter “O.”
For special purposes, such as network testing, documentation, and other applications, IANA also reserves a set of special-use domain names. This list contains domain names such as example, local, localhost, and test. Other top-level domain names containing trade marks are registered for corporate use. Cases include brands such as BMW, Google, and Canon.
If you’re still with me then you might be wondering who came up with all of this. The answer is ICANN — the Internet Corporation for Assigned Names and Numbers. ICANN is a non-profit whose role is to coordinate all the names and numbers that keep the Internet online. They outsource a lot of the heavy domain name lifting to registries like Verisign, who pay ICANN for the privilege.
The hierarchy of domains descends from the right to the left label in the name; each label to the left specifies a subdivision, or subdomain of the domain to the right. For example: the label example specifies a node example.com as a subdomain of the com domain, and www is a label to create www.example.com, a subdomain of example.com. Each label may contain from 1 to 63 octets. The empty label is reserved for the root node and when fully qualified is expressed as the empty label terminated by a dot. The full domain name may not exceed a total length of 253 ASCII characters in its textual representation. Thus, when using a single character per label, the limit is 127 levels: 127 characters plus 126 dots have a total length of 253. In practice, some domain registries may have shorter limits.
The market-driven principles of the domain trade mean that a domain is only worth as much as the buyer is willing to pay. It is for this reason that criteria such as market potential and usability play such central roles in determining prices. Values can change at the drop of a hat. The price of a domain that was once of little interest to anyone in years past can skyrocket once, for example, a newly founded company takes interest in that same name.
It is also possible to setup a personalised or branded email address that simply forwards email to an existing inbox you may already have elsewhere such as Gmail, Yahoo or similar. This way, you can continue using your existing email address and receive your emails through your branded domain name. To send from your personalised address you will need an email mailbox account.
For the most part, you can pick whichever TLD you prefer, though a few have restrictions -- you can't buy a .edu domain unless you run an accredited post-secondary school. Many, but not all, country-specific domains (.us, .uk, .jp) are restricted to citizens of the country in question. Unrestricted country domains are often used for "domain hacks," where the extension becomes part of the title, such as YouTube's alternate address, "youtu.be."