Keeping my pc safe online

I always make sure that I keep my pc safe online. Hackers are rampant nowadays. To keep my pc safe online---I update Windows a least once or twice a month to get the latest updates from Microsoft. I have Firewall, Windows Security Alert. I heard about Zone Alarm that prevent programs from accessing the Internet without your permission, and block access to your PC from intruders. I don't have Zone Alarm but I would surely download it in one of these days. I check for spyware and virus. I browse more safely by using Firefox which blocks pop up ads and to be doubly sure, I use Yahoo search sometimes because it scans bad sites using Mcafee features.