1. Once you have made changes to website it is best to Preview your website on your machine first, click on the Preview button on the Toolbar.
2. When you are happy with the changes and are ready to publish then Click on "Publish your website on the Net" from the Publish menu in the toolbar
To Publish on changes to your website, make sure the box "Publish All" is NOT ticked
To Publish the whole website again then Click "Publish All" box in the window below