•Unfortunately, there aren't any built-in website blocking features in Google Chrome, at least in version 12. Perhaps in the future they will support such feature which would be very useful indeed. However, there are several 3rd party Google Chrome extensions that can help you. Chrome Nanny and Website Blocker are probably the most popular website blocking extensions today. You can block an entire website or a particular subdomain of that website. Or you can limit accessing certain websites to 1 hour a day for example or even set specific time intervals when you are allowed to visit blocked websites. The only problem is that you can't set admin or master password so anyone can easily add/remove websites. And another problem is that some of these extensions do not work in Incognito mode. You can find Chrome Nanny, Website Blocker and other extensions by checking out the Chrome Web Store.
Alternatively, you can use your HOSTS file in Windows to block certain websites. It is also worth mentioning that editing HOSTS file affects all web browsers, not only Google Chrome. The file is located in C:\WINDOWS\system32\drivers\etc directory.
Open your HOSTS file using Notepad.
Ignore lines that start with #. By default there should be only one entry and you shouldn't change it:
This is a reference the local machine by IP address. You can add as many entries as you want to the HOSTS file. Let's say you want to block facebook.com. You just need to add such entries to block:
We are telling our local machine that Facebook actually exists on the local machine and as a result you'll get a blank page instead of facebook.com. Please note that in Windows Vista and 7 you can change HOSTS file only if you have administrative privileges, i.e., open HOSTS file as the administrator. Otherwise, I'm afraid it won't work.
If you want to block pornography, gaming sites or other questionable website by content you should use parental control software or internet filters. My favourites are K9 Web Protection and Net Nanny. You can read more about parental control software here: http://deletemalware.blogspot.com/2011/06/parental-controls-and-internet-filters.html