Some domain names are only available at auction. For now, we’ve chosen to feature buy it now domain names because they are often available immediately. We are working to improve our search engine to make it easier for advanced users to choose whether they want to include domains at auction (or domains with hyphens and numbers) in the search results.
In the first quarter of 2015, 294 million domain names had been registered. A large fraction of them are in the com TLD, which as of December 21, 2014, had 115.6 million domain names, including 11.9 million online business and e-commerce sites, 4.3 million entertainment sites, 3.1 million finance related sites, and 1.8 million sports sites. As of July 2012 the com TLD had more registrations than all of the ccTLDs combined.
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.
If you ever change your web host (the actual physical location of your website files), your domain name goes with you. Your regular visitors or customers who knew your site name as (say) www.thesitewizard.com would not have to be informed about a change of web address (also known as "URL"), since as far as they are concerned, the site is still at the same place. They would simply type your domain name and they'd be transparently brought to your new location.
If you already have a web host, obtain from them the names of their primary and secondary nameservers. Don't worry if you don't understand what these things mean. Just save the information somewhere. The information can usually be obtained from their FAQs or other documentation on their site, usually under a category like "domain name" or "DNS" or "domain name transfer" and the like. If you can't find it, email them. You'll need the information to point your domain name to your website after you buy your domain. Having said that, if you don't have a web host yet, don't worry. Just read on.
Absolutely. Owning 'yourname.com' (as well as related domains such as yourname.tech or yourname.me) is a great way to brand yourself and retain control over your name's online presence. With a personal domain name, you can set up a portfolio, blog, or hobby site that’s associated with your own personal life. You can also set up a custom email address like email@example.com allowing your visitors an easy and memorable way to reach you. So even if you have no immediate use for yourname.com, it's wise to register a personal domain to ensure that you (and not some stranger) control your name online.