You will need to create your account with google and register your sitemaps. You can do this by following this link. https://www.google.com/accounts/Serv...Fhl%3Den&hl=en

You will need to set your information up on the google side. Google will need to know what your website is and what type of files you are submitting. You will also need to verify your website with google. They will have you place an html file in your root directory. Google will search for this file. Once it finds it, you will be verified.

Once you have the google portion of your website setup, it is as simple as just creating the file and telling google that they are ready. (Google Sitemap Admin) will do this for you if properly configed.