Hello Namsters! Here are some thoughts on keeping the bad stuff off of your laptop or desktop:
Anti-virus - 3 favorites of mine are Avast, Kaspersky, and AVG. A couple that have fallen in the ranks of the techie folks I talk with are Norton/Symantec and McAfee. I recommend you do some research and choose one of the first 3. A special note about running more than one anti-virus program; I am having good results running Microsoft's free Security Essentials with Kaspersky. Though David Perdew's advice about performance issues from using 2 AV programs is solid advice, but you may want to test. I do know the "Big Two", Norton and McAfee will not play well with any other AV program.
Firewall - The firewall in Windows is adequate, if you are in a high risk situation you may want to add Zone Alarm, Comodo or Eset Smart Securtiy (makers of Nod32 Anti-virus, a top 5 rated product).
Common Sense: Whoa!!! Where do I download that? Nowhere! You have to take responsibility and engage your brain especially when your are away from your home office. Be careful on wireless networks and use strong passwords to protect your laptop and data.
Backup is your first and final defense! When all else fails, a current and tested backup is your insurance of recovering from a severe attack from the hackers. More information on these and other topics are available on my blog.

Leave comments, questions and recommendations and we will all learn from each other!