1. Open your browser and go to www.opendns.com.
2. Click link "Create a free account" on the top right corner.
3. Fill in the form, open your email and confirm your account.
4. Login to OpenDNS with your accont.
5. Click Setting icon.
6. Choose your filtering level and click customize.
7. Set the category sites you want to block then click Apply.
8. Now go to your DNS setting and set to 208.67.222.222 and 208.67.220.220.
Have fun ...!