When you have created your site, only one step is left to publish it. You need to find a hosting service. You can pay for a yoursitename.com domain, or use a yoursitename.freewebhosting.com domain to publish your site. Simply use a search engine, and search for web hosting or free web hosting solutions. After you have found your host, simply follow his instructions.
The final step is to upload your site to a server with a FTP client like Core Ftp lite (this software is for free). That's it, your site is now on the web. Congratulations! ;-)