Auto complete website URL in Mozilla Firefox
Every time you will have to type a website addresses in your address bar you can easily auto complete the WWW. and the .com part ending by using this trick.
Type the core of the web address, for example say Google, and then instead of clicking enter directly, hold the control (ctrl) keyboard button, and you will find that the WWW. and the .com part is auto filled by the browser and you will be taken to that page.