Comodo Firewall

I had to uninstall NIS 2005 and am now looking for a reliable and easy-to-use firewall. Someone has told me abut Comodo, which I downloaded.
However, I am a novice with computers and firewalls, etc., and am a bit hesitant about installing it because I wouldn’t know what to answer for questions asked during download and installation. Secondly, I would not know how to set-up the various controls within Comodo firewall after it is downloaded.
Is this an easy program to download and use? Are there a lot of options to be checked or unchecked in Comodo firewall?
Can anyone help me. I don’t want to install it and then find out I can’t configure it for optimum service.

Alice Z

P.S. Do I have to do weekly download updates, etc.? I have WinXP sp3; IE 7; AVG 8.