Anti-Virus, Anti-Spyware and Firewall Help?

Hey all.

I'm getting a new computer soon, one all to myself. I am planning on doing alot of downloading and pretty much everything, so I come to you in need of help. I need a free, non-trial version of some Anti-Virus, Anti-Spyware and a Firewall. I also know that I won't get the greatest protection from that but atleast it's still something.

Thanks so much.

EDIT: I'm also looking for a simple OS System with Virus protection in the form of Linux or something like that.

Thanks LRT, I'm gonna use that or Avast!

AVG Free. I use it, and I like it.