AV: Currently there are no virus's in the wild that act against OS X. None. If you feel the need for AV software, without the need to line the pockets of the FUD mongers, consider ClamAVX. It is FREE, always a good price and is available here
Firewall: OS X has a built-in firewall that is accessible from the Sharing Preference pane. (System Preferences > Sharing and choose the Firewall tab.
This firewall only blocks incoming stuff. If you want to be able to control what goes out, or what phones home, consider Little Snitch available here
This one is not free.
Hope this helps
P
I have been using Windows-based computers and decided to try out a MAC. End result using my Macbook/Pro - I love it. So easy. I am concerned about one thing...On my other PC(s), I ran a anti-virus and firewall program(s) and the Mac tech says Apple has one internally installed and there is no need to subscribe to another one. It this true. Makes me nervous not seeing something flashing at me which tells me it's doing its job. Can anyone advise me on what is the best thing to do?

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