Squidguard3 + Active Directory

[Itg]

Hello, using Squidguard3, can restrict Internet access by user or group of users? For example. John uses the computer-05 in the morning, so it can not access social media. In the afternoon, Maria use the same computer-05, but she is allowed to access social media.

How can I separate it?

Another thing, anyone here know a good tutorial for pfSense configuration with Active Directory to authenticate users on the Proxy transparently?

Thank you !