Steve Stevens,
It sounds like you are looking for a definite configuration of applications to keep your computer safe (and who isn't?), but without understanding fully what each is for.
I am using Avast as one of the main features. So are many others.
What I suggest is to learn something about a layered protection strategy. That is, finding out how malware can install, and as best as reasonably possible, plugging the holes.
By the time an antivirus warns of a potential infection, ideally, the plugs put in place should have already stopped most of them.
This would include hardening the browser. (Firefox with Noscript works well.)
Preventing known bad sites loading. (Spyware Blaster, by Javacool, and/or a Hosts file, both updated every week or two, would help.)
Preventing "stuff" automatically loading in a non-Firefox browser. (Set the security options in a browser to "prompt" for any scripting/ActiveX.)
Keeping all software patched. (Have a look at
http://secunia.com/products/consumer/ and perform an online scan. Maybe download and install the PSI.)
Backup your important files regularly. Makes it much less stressful if you need to format and reinstall.
Choose good passwords.
Last but not least, a 2 way firewall is a safety net. If badapplication1234a.exe gets on to your system, a firewall will alert you if it tries to connect outbound.
There are other possibilities. Such as limited user, sandboxing/ virtualization, behaviour blockers/HIPS (Comodo and OA firewall include a HIPS module - basically a whitelist-based allow/deny blocker) imaging software, and a few others. For more advanced users, in some cases.
Most of the various protocols I use are in my sig. Seems to work.
Hope that helps.
