Before getting an account for the app store, you need to understand some of the options you will be offered and a few of the choices you will be making.
You will need a Microsoft account, which used to be known as a Windows Live ID. You probably have one already; it's an email address plus a special password you gave to Microsoft. If you use a Microsoft email provider, such as Hotmail (hotmail.com), Windows Live (live.com), or Outlook.com, then that email+password will serve as a Microsoft account. If you have multiple Microsoft accounts, ensure that you have logged into the one you want to use before starting the process of acquiring an app store account.
There are two account types in the Windows Store: Individual and Company. Both require a registration fee, though Microsoft is making codes available through various channels to reduce or eliminate the fee.
As of this writing, Individual accounts are available only to those testing the app store, and require a registration code straight from Microsoft. However, it is expected that these accounts will be generally available once Windows 8 goes into general release.
Company accounts require additional verification. Two email addresses are needed, and a verification process will be performed involving both of them. Both email addresses can be yours, or the second email address can be a different person in your organization.