The best way to add meta tags is with iWeb seo tool. If you use any other methods you will have to enter your tags every single time you want to make changes to your site. With seo tool you enter your tags once and then just press one button to update your entire site. Here is a download link for it;
By DNS stuff do you mean verifying your site with webmaster tools? Make an xml site map file by following these two tutorials;
See this topic for how to (and how not to) add meta data to the HTML files...