Well, up to us in a strictly volunteer, rag tag kind of way. We really don't have a way to organize our volunteering that isn't somewhat fractured, too. It shouldn't be up to us to get information out to newcomers. Only if we want them to join the communities we're involved with. But it would be nice if there was somewhere to give them those options as they come in the door, not after they've been here floundering around for a few weeks when they stumble upon a post.
I think what you provided for links is good because you do have the personal experience with them, and know what the people in each community are like. You've set yourself up as a representative of each one, at least in this post, and so you're endorsing them. I don't think you need to try do that, or would want to, with communities you're totally unfamiliar with.
And really, it doesn't take super involvement, but it does take some.