Hacking into an insecure Wireless Network

I am attempting to hack into my new wireless network from a second I
already have in order to test it's security. I've figured out how to
hack WEPs and all that and am convinced that a home wireless LAN
cannot be totally protected (perhaps without VPN, etc.).

Anyway, my question is this. Let's assume my access point is insecure
- no WEP set and/or I know the passwords.

I have been unable to map any drives or FTP into the IP addresses
and/or machine names becuase they are protected with passwords. So
why should I care about whether or not my access point is compromised?

I guess I'd like a couple examples that show me how to get actual data
from a machine on a wireless net...

Thanks