If you have the system that has your personal files hardened against any type of attack, then it wouldn't matter if anyone cracked your wireless or not. But if you have printer and file sharing enabled, and/or other entry points avalible, then you could have a problem.

On my wireless LAN at home, I have 3 computers that use it to share an internet connection. I have the SSID, Password and Admin/User accounts changed and password protected. Encryption is used also.

But I am assumming that some one could crack my system, and enter my LAN. So, each computer is set up as a seperate enity and hardened the same as if it were directly connected to the net.

I don't use any file sharing between computers and if I need to print something on the computer with the printer, I simply burn it to a cd or send it as an attachment in an e-mail.

This works well for me, but you might have different requirements that demand you use file sharing and such.