You must go to C:\wamp\www\ and create a new folder for a project. Say for example you have a website on tea cups. Make a folder relative to this an put your project files in here (C:\wamp\www\teacups).
Once this is done typing http://localhost/ into the browser should show all the project folders in the \www directory. You should click on your project (in this case the folder "tea cups" and then your website will be shown.
Hope this helps,
WAMP server is amazing!
Personally, I like XAMPP, but its all bananas and apples. If you organize your local sites:
c:\wampp\www\teacups\ (http://localhost/teacups/) and then upload to remote site - you'll find that your internal links might not work. You may need to change your 'hosts' (C:\Windows\System32\drivers\etc\hosts) and 'httpd.conf' (c:\wamp\Apache2\conf\httpd.conf) files. See this site for a full explanation: