Which is a good software used to block facebook?

Some computers have parental controls already installed. If you look under your security or network settings, you may be able to change it. If not, then you can go to www.fbblocker.com. I hear it works.

For Firefox, the LeechBlock extension should do nicely.

For all browsers, I highly recommend K9 Web Protection. Easy to install and use.

On a slightly different note, you could also try using RescueTime to monitor your Facebook usage. It won’t block FB, but seeing how many hours you’ve lost on FB in a week can be a wonderful motivator…

You can set your router settings, but if you want software I recommend this one. www.facebooklimiter.com