In Opera, simply press Ctrl-Alt-V to have your page validated. If you haven't yet installed Opera, go to http://validator.w3.org/
You have the option of validating your page by typing in the URL, or uploading files from your computer.
When your code is valid, you go to a Validation Results page that tells you how to get the logo.
If this is your first time using the Validator, it may be rather confusing. Feel free to ask about the results. Just remember that the Validator does not think like people do. Where I would have said you are missing the closing /head tag, the validator will list everything that follows (or should follow) that tag as "not allowed here".
