You can never be too careful, as they say, and I say
to you. I only run one firewall on my computer, relying mostly on my modem's nat router which only allows a select few incomming ports to be forwarded. If MSN want's to hack into my computer they can go ahead and try, they won't find anything to sue me over; just to be safe, though, none of the unlicenced software I use is from Microsoft. I keep filesharing to a minimum on public networks, I hate to be a leech but that's the way it is. I run Ad-Aware fairly often. Besides that there's not much more I care to do, but I think on the average my computer's much safer than the majority of internet connected machines, and I'm a relatively samll target.
What I'd like to see is a website with tutorials for newbies to learn about protecting themselves. Something that covers the basics and gives links to more advanced techniques. GRC.com is a good resource but it's fairly technical and his postings are long winded. And websites that sell security products, even good ones, are more interested in sales than educating consumers. If someone was willing to help me set up a security for dummies website I'd be willing to host it.