To be honest, clans used to handle this, but clans don't seem to recruit like they used to in NA. Maybe the newer clans do. That's probably about it. Anyway, if we a saw noob - especially in duel - we'd teach them the ropes via text and then invite them over to voip if it seemed like the person wasn't a douche. There, they'd learn the rest. I'm sure it still happens, but I know I personally don't do it anymore- mostly because the game is more balanced than it's ever been before, so it's harder to tell who's a newbie and who's just bad. People seem to learn the game much more quickly than they used to, anyway, and I believe the regular playerbase understands everything about the game these days.
I've always thought that part of the fun of the game was the learning curve, and, when you finally got all the basics - recognizing individual fighting styles and tracing the lineage of teachers and dueling partners though that style alone.
I don't really see that individual personality any more, so perhaps people don't feel the need to teach their own method of playing to every newbie who wants to learn. There's no branding, really. Everyone fights almost the same ways these days.
I remember when I started in december 2010 I followed the beginners guide religiously. Get shield skill, hold up your shield, find a shiny guy, follow him. Get a polearm like a pitchfork, help your shiny guy by poking at baddies. Good times, good times. I don't know, for me it just makes sense to go on the forums and read guides when I get into a new, complex looking game.
I think that might've been part of it, too. You picked a skilled/crutching player to hide behind and hoped he killed the bad guys for you. Every now and then you'd poke someone for him, and a relationship would begin in cyberspace. That person usually taught us the basics, I think, even in the form of insults like 'learn to read holds, noob'.