Here are my first steps for a novice user:
1) Install a Firewall- Zone Alarm (basic which is free)
The other options are : Just make sure the firewall built in with Windows XP -SP2 and above (incl. Vista) is on!
Although the built in firewall leaves much to be desired and the fact that they never seem to be updated (i use windows update and haven't seen a single update for the built in firewall on windows, ever) is reason to believe they are no good.
One always hears about antivirus,antispyware etc. but rarely about firewall, but this one is essential.
A good firewall that even prevents unauthorised outward access is recommended.
Typical scenerio 1: You have spyware on your system, it needs to send data back to its creator to be of any use. You being smart, have firewall that alerts you of an applications desire to use the internet, an application whose name is suspicious, one that you don't use, you block it. Saved.
Scenerio 2: You have virus on system. Many viruses today have a party on an infected system by inviting (downloading) all their friends from the internet onto the system. You being smart, have firewall that alerts you of a applications desire to use the internet, an application whose name is suspicious, one that you don't use, you block it. Saved. Of-course the one virus still remains to be tackled by other means (get a different antivirus etc.)
2) Install Antivirus - Too many to choose from , use any thing as long as you've seen/met 10 people who use it. (Examples: AVG free 8 -SP1 (latest, as the initial version was plagued by problems) or Avast (free version), Avira (free Version) )
Most Important: KEEP IT UPDATED
3) AntiSpyware - Use any but again ensure it is well updated. Treat it on par with Antivirus. Today spyware is as big a threat as virus and it has become increasingly difficult to differentiate between the two.
Examples: Built in with the antivirus!!!, Windows Defender from Microsoft, Spybot Search & Destroy, Lavasoft Ad-Aware 2008.
4) Browser: Use any, but make sure it is the latest version.
This is also one of the most neglected security issues. Most users do not even install a browser but use what is installed with the OS which will be IE 6 on Win XP sp2. It is most advisable to use the latest IE7 with the phishing filter ON.
Examples: Internet Explorer (IE), Firefox.
5) Prevent Pen Drive Virus - This is a strange one and most difficult to fix, but most pendrive viruses like Shahrok.exe, Muha-ha-ha and countless others are not detected by many antivirus software (Even the paid ones) until it is very late.
So try not to take pen-drives to cyber cafe etc. and then use in your computer.
Hope this article helps users new to the internet or comp to keep their pc secure, and for the seasoned users hope you remembered to update and scan ur pc!