yes, but 000-default file should be left alone with standard directives for your DocRoot /var/www/
then you should put directives for any other web site you are going to add in a separate file in /etc/apache2/sites-available/ and then create a symlink to it in
/etc/apache2/sites-enabled/
so you can simply remove the symlink if you ever want to put sites offline instead of commenting out lines on a single, maybe huge, conf file, moreover you gain better control on per site directives
(before going online)
http://httpd.apache.org/docs/2.2/regards