NO MATTER WHAT I DO, I CANNOT CONNECT through a proxy server!
I am connected to the internet through a D-Link router and I am running Mozilla Firefox and Norton Protection Center.

What I did was find a list of proxy servers. Here is an example website I used: http://www.publicproxyservers.com/page1...
I edited my "Manual Proxy Configuration" in Firefox. I entered proxy server IP and port numbers for both HTTP and SSL

Firefox can't connect to any of them though! I just get the error message: "The connection has timed out" The server at Google (http://www.google.ca) is taking too long to respond. It does this with EVERY website and EVERY proxy server!

Any help would be greatly appreciated!

All right there could be a few things blocking it
#1 NPC (Norton) could be blocking 8080, 1080, 1020, 8000 or whatever port it's using
#2 70% of the proxys out there are dead
#3 Why are you wanting to us a proxy? You can use a CGI proxy which is just as good.