To verify your site with Google Webmaster you need to use the HTML Tag option under Alternate Methods. Do not use the Recommended Method as this will not work. It is also very important that you copy the correct portion of the tag in order to be successful. Copy only the letter/number string between the quotation marks, then click Settings > Tracking. Paste the code into the Google Webmaster field, and then click Save Changes.
For detailed, step-by-step, instructions on how to verify your site with Google Webmaster and submit a sitemap, please see Yola’s Google Webmaster Tutorial.
Please use Yola’s instructions and not Google's. Google's are written on the assumption that you are coding the website from scratch. Yola’s instructions are written to work specifically with Yola.