Dansguardian will probably serve you well andf you will get AV scanning to boot.
http://forum.pfsense.org/index.php?topic=42664.0
pay attention to the section on HTTPS and forwarding to 8080
This is a more recent write up:
http://thegeekninja.wordpress.com/2013/07/02/pfsense-squid3-and-dansguardian-a-better-alternative-to-squidguard/
I would stick with the stable release of squid rather than use the squid3 beta.
Dansguardian is a package now so you can add it directly from package and no listing of commands is needed.
Go into the ACL (access control list)
Disable all the filters you don't want
Make sure URL list is enabled.
Edit the regexp in the banned section just adding the url of things you don't want people to see.
like youtube.com
facebook.com
whyisuckattyping.com or whatever.
It will be easier to make a firewall rule for you if you make an alias including all the machines you wish to filter.
For me, I disable all the filters except url and antivirus scan.