Passwords are like toothbrushes - you shouldn't share them with other people, and you should get a new one every now and again.
See ChoosingPasswords for information on creating safe, random passwords.
netstat -apAinet
(You'll need to do this as "root" to get all process information). The lines that say "LISTEN" means a daemon is waiting for connections on the specified TCP port. Don't forget to check your UDP ports too - all sorts of things can lurk there.
See also SecuringYourBox (or refactor it to here.)
GNU Privacy Guard (GPG) is an encryption program compatible with Pretty Good Privacy (PGP). It uses public-key cryptography, and many email clients have hooks that allow you to fairly easily encrypt and "sign" email. See our GPG/PGPNotes page.
See WirelessNetworkSecurityNotes
3 pages link to SecurityNotes:
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