No good comes from content blocking.

If you don't want to see any porn, then don't browse to those sites, it's as simple as that.

Now you are going to regret asking this question somewhere down the line. I guarantee it.

The best way to block websites is at the router.

OpenDNS is an alternative DNS service (URL domain lookup - you see it's like each website had it's own phone number, these are called IP addresses. One of the many that Google own is 74.125.127.100 In order to have an easy to remember name such as google.com that domain has to be registered and DNS servers must recognize it and translate it for the client computers' web browsers.

Now OpenDNS offers a public DNS (alternative to what your ISP offers) at 4.2.2.2

But for what you are asking you'll want to create an account with them (free) follow the directions on how to add the DNS ip to your specific router HERE and then login add your "network IP" (your outside IP; it detects it automatically) and from there you go to Settings (in Dashboard) and you should see something like this http://s3.lookpic.com/i/699/kRVxBsXc.png

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Ok now I'm going to show you how to break this system (you may need to follow these basic directions anyway if sites don't load)

Learn to love Linux CLI. Start up xterm (or alternative)

Become root with one of the packages. Might be be $ root or $ becomeroot or $ su - just depends on which package you chose.

# ping google.com
output should be something like this
CTRL+C to stop pinging.

# cat /etc/resolv.conf
output should be
You might need to add the IP address of your router (typically 192.168.1.1 but varies)

You might also need to add the DNS address that OpenDNS assigns you to get content blocking to work.

Now to break the lovely system I described above (=
Simply plug in a public nameserver such as the RoadRunner DNS servers

nameserver 209.18.47.61
nameserver 209.18.47.62

Or learn to how to gain admin access to the router...