Best programs to protect kids from porn /monitor on internet?

Talk to them about stuff before its a "thing." No matter what you do their friend from school will have figured out how to get around the school firewall and get to the "good" stuff on the Internet, and if you're kids haven't been talked to about it yet they will be at the mercy of their friend describing how they should interpret it.

You want them to recognize when predators try to create a chat session with them, how their presence on the Internet is perceived by others, and some basic eye opening about the wide variety of behaviors people get into once they are adults (and mid teens). For my daughters we started talking about this around the dinner table when they were about 10.

If your on a mac, a lot of what you would want to see works OOTB with no fancy solution.

If your not on a mac your going to want more than openDNS, more along the lines of a full fledged proxy.

Take the first few opportunities to educate and let them go figure things out for themselves. You will both be happier with the approach... If you create limits they are going to figure out how to get around them (friends, starubucks, neighbors wifi).

http://www.websafety.com offers a monitoring solution which informs parents of suspicious activities.

An ad blocker is important. I'm not a fan of ad blockers in general, but there are so many awful ads out there that young children definitely need them.

Adblockers on browsers can help a bit.