Just go to the URL http://www.google.com/webmasters/ & sign up with your Gmail ID. You will get all Google Webmaster relation solutions. Let me know this suggestion is helpful or not.
I am not getting your question clearly you want to reg your site in webmaster tool or what? If you want to use webmaster tool for your web site means just login to webmaster tool using your gmail, add your site and place the verification code in your web site and verify. then automatically it will start noted your back link, keywords, crawl error etc...