I was 7/8 in 2003/2004, but I remember it quite well.
Most of the informations were coming from Rockstar's official site and the magazines (including screenshot scans). Even without YouTube, Facebook, Twitter and all that stuff, we were pretty well informed about everything what's been going on. A couple of days before the release date, some gameplay videos leaked onto the net.
In some sense, those were better days, I say. Today we have the HD technology, developers release screenshots from their games more than ever, the Internet is faster and it's much easier to watch those trailer and screenshots over and over again. It breaks the part of "I wonder how the game will look on my own TV", if you catch the meaning. We start to experience those games before they're even released. And that kinda ruins the magic, when you finally launch the disc with your most anticipated game.