I lost my directions on how to install my WRT54G

If you go to the link I have provided below from the Linksys site just finput your version number (it is usually on the bottom next to the model number).
Then it will give you access to the manuals and the updated firmware for you Router (while you are there you might as well to that too, *it is importrant!

http://www.linksysbycisco.com/US/en/support/WRT54G/download

On her computer, click START
Click RUN
Type CMD and press ENTER
Type IPCONFIG and press ENTER
Look for a line like: Default Gateway . . . . . . . . . : 124.168.136.11
Type EXIT and press ENTER
Open a web-browser (IE, FireFox, Google Chrome, etc.)
Enter: http://124.168.136.11
to access the router's web-interface.
Login -- try ID of 'admin' with a "blank" password;
try a "blank" ID with 'admin' as the password;
try ID of 'admin' and password of 'admin'.
Click on the "Wireless Setup Wizard" button.
Configure the router for wireless access.

On your laptop, refresh the list of available networks.
It should find the newly-configured network.
Connect to it.