Well I just wrote this article to help Prisma out a little bit, but I figured I would post it as a thread seeing as it's pretty long/detailed. I will be posting some more articles later.
My background: I manage many networks for small businesses and currently have my MCE and MCSD.
1. Download Sygate Firewall, it scans all incoming and outgoing packets making your PC virtually "fenced in" to threats. This is your biggest priority, it can be downloaded here:
http://www.download.com/Sygate-Perso...ml?tag=lst-0-1
2. Spyware/Adware Tools: These vary GREATLY, it really depends on what your preference is. I personally use AVG's Anti-Spyware 7.5 because it (again) scans all incoming and outgoing packets making your PC (again) virtually "fenced in" from threats. There are other programs such as Ad-Aware that are very good at removing spyware/adware, but that's all it's good for -- REMOVING. It does nothing to prevent threats. That is unless you download the Pro version (costs money) that comes with the "Ad-Watch" plugin, which is still virtually useless because all it does is monitor registry values.
I manage networks for small businesses -- if you want a straight forward answer from me I suggest you just download Sygate firewall, and then get a "Resident Shield" anti-spyware software w/ a built in scanner. This will block them from coming in and you will still have a nice scanner just in case something gets in. An example of a good software like this is AVG Anti-Spyware 7.5 (free).
3. Anti-Virus: Alright, this is another big thing -- most antispyware/adware softwares won't protect you against this. So you can either get a software that keeps threats from coming in, or gets them out quickly/easily once they ARE in. Or you can get a program that does both. Some examples of good programs for this are Norton Anti-Virus (NOT recommended if you have anything under a Pentium 4 and less than 512mb RAM, great if your computer can handle it and if you can afford it.), AVG Anti-Virus (Great program, used by many network specialists and has an excellent built in scanner and "always-on" shield to protect from incoming viruses.
My final software choice:
I currently use all of these on my desktop/laptops.
1. Sygate Firewall
2. AVG Anti-Spyware 7.5
3. AVG Anti-Virus 7.5
4. Clam-Win Virus Scanner
All free programs with great protection. Also easy on the memory.
Keep in mind that many people are highly skeptical about software like this, they believe that one is better than the other. This is true in some cases but often it's just because the user likes the look of one program, and it happened to detect a virus for them so it "MUST BE THE BEST SOFTWARE OUT THERE". Your best bet is to spend some time on google, read a lot of reviews, and test out different programs to see which works best for you.
Heres some things to get you started.
http://reviews.cnet.com/4244-5_7-0.h...g=srch&target=
http://www.google.com/search?hl=en&q...&btnG= Search
http://anti-virus-software-review.toptenreviews.com/
http://www.pcworld.com/article/id,12...1/article.html
Side note: Don't download a piece of software just because it's popular, do your own research on it and choose which one you like the best. I'm a firm believer that the best software out there is NOT the stuff that costs money. Open-source software is the way to go.