Perfect. Try clicking here
to see if you can get to the login page for your router.
If it asks you for a user name and password, leave the username field blank and type in admin for the password.
After logging in, you will see a wireless tab at the top. Click it. From that screen you should see your wireless network name SSID. You can change this if you want to. If it is set to linksys, I highly recommend changing it to something else to help avoid confusion. Make sure to click save if you do change it.
Now click on the wireless security page. There you will be able to see your encryption. From here you can select your encryption type. Depending on your options, WPA-Personal TKIP is normally the recommend setting for most computers. Select it or any other encryption standard that you may want.
Now you we need to put in a network password (Pre-shared key). This is the password XXXXX will be required to connect to the wireless. Remember to hit save again.
Now test your new settings on your wireless computers.
If you have any problems with any of the steps, please post back and I will gladly further assist you.