Most popular routers offer some sort of “parental control” or “internet access policy”.
The key for many people may be remembering how to use that administrative panel.
Since we don't know what browser or OS you're using, you'll need to pursue it from there. Also, they should be prepared for the distinct possibility of a malware infestation.
A good program for doing this that works with most browsers is CCleaner. A lot of porn sites really know how to, if you'll pardon the pun, screw their visitors over.
Yes/No; While it is free to use, POF offers premium services as part of their upgraded membership, such as seeing the date and time a user viewed your profile and allowing you to see whether a user read and/or deleted your message.
Fall is my favorite season and for some reason it brings in the most reader questions.
If you need to restrict access, Open DNS has over 50 category filters covering the usual suspects.