I'd like to encrypt my w'less connection

If it isn't already. I have a Router + Modem w/ broadband connection and have tried repeatedly to encrypt it and have the other wireless devices in the home enabled to access it, but I do not know where I have gone wrong.

I'll post more information later on (I will need to gather specs and settings information) but in the mean time is there any specific information needed first?

Thank you.

 

Here is a good site for general information -
http://www.ezlan.net/Wireless_Security.html