Google Checkout is a way to receive payments for products and services using Google's payment system. To add a Google Checkout "Buy" button to your website follow these steps.

Step1. Go to http://Google.com/checkout. Login to your account with your existing Google user ID or create a new one.

Step 2. Once you have logged into your account click on the 'My Sales' link near the top of the page.

Step 3. Click on the tab labeled "Tools".

Step 4. Choose the style and type of buy button you would like to add to your website.

Step 5. Copy the HTML code for your buy button to your clipboard.

Step 6. Login to your account and choose to edit the page you would like to add your buy button. 

Step 7. Click Insert> HTML Code, paste the code in the area provided then click 'Ok'.

Step 8. Position your buy button where you would like it to appear on your web page.