Believe an anti-virus vendor's marketing spiel and you might end up with a naff product - so do your homework.
Pay attention to the Macs in your office, especially if they are used by people unaware of the risks they present.
Password re-use, not to mention default and blank passwords, can bring your whole network to its knees.
Sensitive data can be tunnelled out of your network in many ways. Fortunately, there are just as many ways to stop it.
Wireless sniffing tools can tell you - and potential wrongdoers - a lot about users of mobile devices.