Well, seems an alright place to me.
I think the thing about the info is that this project has been around for a really really long time, and this is at least its second sort of reincarnation, haha. A lot of the old stuff that isn't really relevant anymore... well, all of the old stuff was archived, and isn't viewable by the majority of people anymore.
So, summary time! You're completely right, this is a community-made fan game!
This topic,
current design info, outlines a lot of the plot of the game, at least, as much as we've decided so far. So that can kind of give you a taste of where the game might go. In the level design topic, there's a screenshot from one of the old King of Thieves iterations, which could give you a view artistically.
As for how to help out, the system in place now is that there are divisions, game design, software development, art, sound, and Level Design. People can join a team or two. Mostly just game design and levels are active right now, and those teams are already full, I believe.
However, as this is just a small internet forum that is apparently constantly on the verge of death, lots of teams have people going MIA. I'm directing the Game Design division, and I've had one of my team disappear. The Levels team seems to be at three at the moment, too. Anyway, since I'm missing a member, I'd gladly accept help if you'd like to join in with game design.
But when I last looked (which was just now), there was one more opening on the art team, which will be doing spriting. Sound team hasn't opened up recruitment yet. So just post something in the art recruitment thread if you'd like to help out with spriting, wait for the sound team to happen (could be a while... o.O ), or if you'd like to help out with game design, I'll welcome you to the team.
Also, since this kind of is the wrong place to ask, that makes this the wrong place to reply, so sorry, MG. But there isn't really a right place to ask/reply, so... : D