Click “Create an account now” and give them your current email address, a password you want to use, select your location, verify you’re human and click “I accept. Create my account.” after reading all the fine print Google has to offer in their Terms of Service. You’re in! Then click “My i-Google” to “My Account." ” If you don’t see this option, use this link:  https://www.google.com/webmasters/tools/  You can verify later, but Google will not allow you to submit your sitemap until your site has been verified. It’s easy to do and they offer an example of where to place their code. Enter the code on your .index page and save. Go back to the verification page and click “Verify.”  www.yourwebsite.com/sitemap and click the “Submit Sitemap” button. That’s it! Google knows you exist! Whew! Google will also track any updates you make, so it’s not necessary to submit multiple times. Maybe once every six months or so; everyone has different opinions here.

Summary:
Go to Google.com and click “Sign In” in the top right-hand corner. Sign-in to your Google account. Go to “Webmaster Tools. Click on the “Add a site” and type in your domain name, for example www.mywebsite.com. Verify that you have access to your website by entering some code to your home page. After your website has been verified, you can click “Submit my Sitemap” near the bottom of the page. Simply click “Submit a Sitemap” on the next page and a drop down box will allow you to enter your extension , i.e. You will receive a message that your sitemap has been submitted.