Don't get hacked
Use strong passwords, yes with characters also £$%^&*()_+_)
Use passwords, change the default passwords shipped with your router
Use WEP or WPA (much better) encryption on your router
Dont upset anyone in hacking communities, there is always someone who knows a lot more than you ;o), oh yes and be nice!
Remove old unused software from your computer and servers (a security risk)
Use up to date antivirus software and firewall software