DOES NOT WORK FOR ME! Blocking access to some websites

    su
    apt-get install squidguard
    mkdir custom;cd custom/;emacs -nw domains
  

Now, enter your domains in the following format:

domain1.com
domain2.org
domain3.net

Then,

chown proxy:proxy /etc/squidguard/squidGuard.conf
    chown -R proxy:proxy /var/lib/squidguard/db    
    chown -R proxy:proxy /var/log/squidguard
    emacs -nw  /etc/squidguard/squidGuard.conf  

Here is an example of the configuration:

dbhome /var/lib/squidguard/db
logdir /var/log/squidguard
dest custom {
        domainlist custom/domains
        }

acl {
        default {
                pass !custom all
                redirect http://localhost/block.html
        }
 }
    
Now,
      squidGuard -C all -d
            
      

References: