1. You should start by purchasing a domain name. Domain Samurai is a great tool that will help you enter in a keyword and then find a bunch of related domains that are still available. I would suggest going to for a .com rather than a .info or .us or anything else for that matter. It is just too easy for people to get confused. A .com is always going to hold more value than any other extension.
2. Once you get it picked out, you need to find somewhere to purchase it. I bought my first few domains at GoDaddy.com
and have bought the remaining ones from my hosting companies. While GoDaddy is about one of the biggest names out there, I can’t say that I recommend them because of some of their advertising campaigns that they run. I now recommend Namecheap because they are very easy to use and as the name suggests they really are cheap compared to a lot of others!