The Domain Name System (DNS) is a distributed hierarchical system to look up and translate a name such as "www.yahoo.com" to the IP address which is used to reach the yahoo server.
Most people use the DNS provided by their internet provider. Some providers automatically intercept misspellings and send the user to their own search page. A good alternative DNS provider is OpenDNS, which provides some malware filtering at the domain level.
You can change your computer settings in network properties to use OpenDNS. If you have access to the router, change the router settings so all of your devices will use OpenDNS.
On a Cisco Valet M20 router, set the following static IP address for DNS. The first two are for OpenDNS:
The third is for Google DNS: