Once you've got the keywords you want to rank on defined, you can grab a unique domain to promote your Guide on.

The ideal domain is fairly short and easy to remember. I'd also recommend ending it in ".......guide.com/guide.co".

If you need help coming up with a domain, check out NameMesh.

This site is pretty awesome as it can help suggest domains based on keywords or categories. I'd suggest always picking form the SEO category once you've added your keywords in:

You can the use NameMesh to register your domain with popular registrars. The site also tells you if the domain is available as a handle/username on Twitter and Facebook (which will be the next steps):

Another very similar tool that will search available domains and social platforms for the availability of a specific keyword is NameCheckr.