A good friend of mine sent me this link to pornproofkids.com:
Lot's of parents get really scared or nervous when they consider talking to their kid(s) about pornography. And, seriously, that is understandable. It isn't a comfortable topic.
It is, however, a very important topic to discuss with your kids. The main point here is that if you don't talk to your kids about pornography, someone else will and they might not do it in a way you'd approve of.
In this day and age, everyone will be subjected to pornography at some point. Help your kids have the necessary tools to deal with those situations when the time comes.
My favorite suggestion, and one that I agree with tremendously, is #5: Name it when you see it. Call it what it is, don't skirt around the issue.
Go check it out and make sure you prepare your kids for when they encounter pornography.