No, not really.
For the servers side i let my hosting company look after it.
They do a good job I have to say.
For my own network, I do everything I can to make sure is safe, but if it's meant to happen, it will. My router has a firewall and I have it programmed to let only certain mac addresses going through.
All computers have firewalls, antivirus and anti-spyware installed, including Windows Defender to top it up, so I am really happy with the way is going at the moment.
I just have my own rules - don't open emails with attachements if you don't expected and don't download anything from website you don't trust.
Don't use Limewire, or Kazza etc...
If you do make sure you don't have it installed on the computer that has all your important data.