Installation on Ubuntu 12.10 – vps

Hi, having some issues getting 3.5.1 working here, followed the manual instructions here http://wordpress.org/support/topic/20-hours-into-5-minute-install after some failed attempts at the apt-get method. This is my first WP install on linux w/o cpanel so I could be missing something basic. Will eventually want to have multiple wp sites running on the same server, but for now would be content to get this one running. I believe I’ve followed all the proper steps w/ config files, sites-available, virtual-host, mysql and apache setups, etc.. not sure what the issue is. After changing the install directory from /var/www/mysite.com/3.5.1 to /var/www/mysite.com/wordpress, navigating to http://mysite.com/wordpress gives a forbidden error – but I know the permissions are 755. Not sure why. If anyone is able to help, please let me know what data I can share to assist. Many thanks.