That's what we're going for. This is a community designed to share knowledge - knowledge of almost anything. Each member contributes by posting a paragraph-or-so of a subject they're familiar with, in their own words. (This sounds suspiciously like an exam, but really isn't.)
Say you know about architecture, or construction. Post a paragraph about how it works, or the history of it, or some inane fact others might not know. If you know about clouds, post about clouds. If you know about textiles or clothing design, post about that. This is seriously a free-range exchange of knowledge across any spectrum.
It doesn't have to be serious, cut-and-dry. If you work at a movie theatre, tell us what the heck you do with the ticket stubs. Post about who has to clean up puke at carnivals, or let us know what your squadron calls civilians when no one's listening.
This is to learn. And to talk about ourselves, and what we know, which everyone loves to do anyhow.
To make it simple, here's a few basic rules.
Know what you're talking about. You don't have to be an expert or even adept at it, but you should know what you're telling. Don't post everything all at once. Posts are good, but if you post everything you can think of in the first five minutes of joining, where's then fun in that? If you're posting a recipe, instructions, or pictures, put it behind an LJ-cut. Recipes are good. Instructions too. Pictures are brilliant. But, it can skew up layouts and Friends Pages. So, but it behind a detailed cut and we can all marvel in awe of it there. Don't be an idiot. The internet has plenty of trolls and flamers. We don't require them. They aren't a necessary part of the community's ecosystem. Post whatever you'd like that can fit here, but don't start wars or try to pass off random internet links as wonderful posts. There are communities for that. (Good ones, too.) Post in your own words. Anyone can find a Wikipedia entry and copy it here. We're looking for your knowledge, in your words. Even if there are repeat topics (say, three different people posting about particle physics), each entry should stand alone because it's from a different source, a different person.
And honestly? Just be a decent person and adhere to normal standards. Have fun with what you post and learn, and regurgitate those facts you're forced to learn all day, 'cause, hey, someone else might not know them yet.