Can't Connect to the Internet

Please forgive me, I'm really not very computer-savvy, so I may ask dumb questions.

Here's the situation: About a week ago, I was suddenly unable to connect to our wireless Internet from my laptop. Our desktop is still connected (I believe it is physically connected, not wireless) as is my brother's wireless laptop, but not my iPod Touch. However, my laptop CAN connect to the neighbor's unsecured router and my iPod can connect on my college campus. Because of this, I have no idea if it's the computer or the Internet.

I've tried resetting the modem and router (unplugging, waiting, and replugging) but that did nothing. My brother typically handles computer issues, but he doesn't want to be bothered and refuses to look into it. I'm going absolutely insane! The signal is strong, it just won't connect.

I'd be incredibly grateful for any advice!!

I believe it is WPA2-PSK, if that makes sense.

I put in 192.168.0.1 and it Authentication Required and asks for a user name and password. Is that normal? I'll have to wait and speak with my brother about either A) getting the user name and password or B) getting the correct address.

That would be my cable company, correct? (Sorry, like I said, I don't know much about this sort of thing)

It's Wide Open West

I believe it is Linksys Model WRT54G-TM