@Mattleonard,
Go To Google Apps for Domains
Submit your website address without typing
http://
Then fill up the vacant blanks with required information. Keep your username simple because this will be attached to your domain name to create your custom Gmail account username. In my case I choose Mohammad for my sister blog.
Keep Alternate email address the same as your personal Gmail ID or any ID that you use frequently.
Click the submit button to create your account
You have now successfully created an account with Google apps. Now you need to verify that you actually own the domain. You will be given two options Express and Custom. Choose express.