Anti-virus on a Mac
I wouldn't bother - there may be one or two viruses that would work on a Mac, but I haven't seen any reports of them. I know people will say it is important, but the anti-virus programs really stop viruses that only work on a Windows machine. I haven't heard of any serious threats for a Mac or Ubuntu machine. There are literally millions of varieties of viruses that infect Windows computers.
Rule number 1: Keep a Time Machine automatic backup in case you click on a really bad email link.
There is no rule number two.
The problem with installing an anti-virus program is that it has to look at every file that is opened BEFORE you see the file, so it can check to see if it has bad code attached. This can really slow down your computer. Apple has included code in its recent versions to avoid being infected with viruses and it seems to work. I haven't heard of any infected 10.9 computers, other than Kaspersky testing. The anti-virus programs that are available will catch and report on WINDOWS viruses. You may be able to help the Windows world by not forwarding emails with Windows viruses attached, but you won't do much for your Mac computer, besides slowing it down.
I support many PCs running Windows 7, XP, W-8, and many Macs. The Macs really do not need my support as they just work. I just make sure they are updated with the most current Apple Versions. Apple is very good at fixing problems before they become serious problems in the wild.
I am sure that many people will respond differently. These are just my experiences in my work as a support tech. Windows (and Android) MUST have good anti virus (I recommend Avast Free), but it's not a real-world problem with Mac 10.9 and IOS, in my experience.
