How Total Validator works
The Total Validator starts with the web page you specify, and performs a number of validations on it depending on what you choose. If you are checking more than one page it then follows the links on your starting page checking all the pages referred to. So if you specify the home page of a web site it should check all the visible pages of your web site that are ultimately linked back to the starting page.
topOnline form
Simply fill in the one-stop validator form and click the Submit button to start Total Validator.
If you're checking just a single page and taking screenshots with a single browser then the results will be returned directly to your browser.
If you are checking more than one page you must also enter your email address. The Total Validator will then run as a background task, which when complete will email you with a zip file containing the results in html format.
Alternatives
The online service may be okay for a quick check. But if you're really serious then download one of the desktop tools for more features, a faster response, and the ability to check off-line/intranet pages as well.
If you use the Firefox browser then there's also an extension that works with the desktop tools to allow you to validate the page your browser is pointing at with just one click.