re: lockdown 101 for Jody
Every computer should have an operating system password set up, but for a home computer the bios password is usually overkill.
I have the screen saver set up to also require the password when you come back to the computer.
It's a good idea not to let anyone use your computer for internet access at all if you don't trust them completely. It's almost impossible to put enough defenses in place so that some dimbulb hitting the internet on your machine can't screw something up.