Google provides a service that lets clients query it from places other than the Google home page. To prevent the abuse of this service, Google requires potential clients to register for the service, and then limits each client to 1000 Google queries per day. Signing up for the service is free and is done online. Once you sign up, you will receive a license key via email. To use Google Dominoes, you must first enter the license key into the Preferences dialog that can be accessed from the Google Dominoes toolbar.
If you have a Gmail account, then you already have a Google account (the Gmail account functions as both), so you can proceed directly to Step 2. If you need to create a Google Account, then visit https://www.google.com/accounts/ to create an account.
Once you have your Google account, you must log in and get a license key. Once you request a license key, it will be sent to the email address that you used to create your Google account.