To use a computer, just walk up to it and log on using your library card number and PIN (your PIN is initially the last four digits of your phone number, but you can change it).
If all computers are in use, you can go the waiting list computer upstairs, or the waiting list/printing computer in Children's, and sign up to be in the waiting list for either the upstairs computers or the Children's Room computers. You will get a receipt with your number; just watch the scrolling, red LED sign for your number to come up. There is no waiting list for the "Express" 20-minute computers upstairs or the word processing computers in Children's; these are first come, first served.
Locking a Computer
If you need to step away for a few minutes, just click "lock" at the bottom of the screen. Anything you have open on the screen will be hidden, and nobody but you will be able to access the computer. When you get back, unlock the computer using your library card number and PIN. Keep an eye on the time, though: If a computer is locked for 10 minutes, it will close all your windows and log you off without saving your work.
If you're logged into a computer and you don't type anything or move the mouse for 5 minutes, the computer will lock itself. You can unlock it easily by typing in your library card number and PIN. If the computer remains locked for 10 minutes, it will close all your windows and log you off.
Most computers can be used for 2 hours at a time. The only exceptions are the four "Express" computers upstairs, which have 20-minute time limits, and the two "No Internet" computers in Children's, which can be used for four hours at a time. There is a daily maximum of four hours on the computers.
When you log off of a computer it reboots, and the reboot process restores the computer to its original state. If any traces of your Internet activity remained, or if you accidentally left a document on the computer, all of this would be erased before the next person logs in. This also protects from the little things that happen over time which decrease the computer's performance.