Just had a really cool, smart guy tell me about the project he's working on. He's building up a site and looking to get contributors. I'm editing out the specifics, but here's my reply to him -
So, the question you've got to ask is - "What's in it for them?" Why would someone put in work to contribute to your site?
Now, later on, the answer is easy - "I have a high traffic, high prestige site, and people want to contribute here."
For now, what's the answer? Well, I think high traffic and high prestige would both help - anything you can do to increase either would help you.
Thoughts on both -
1. Traffic: Why should someone read one of your entries? What are the benefits to a potential reader's life? Why should they share your site with friends?
The better you can answer those questions, the more your traffic will grow. To this end, you might consider having a brainstorm on who you can make each piece you create appeal to. For instance, a piece called "Running - Pacing and All-out effort" - and then talk about how runners make the judgment call. In that case, that entry will be useful to runners and sports people, and you can potentially promote it in runner/sportsman places, and runners/sportsmen might share the article amongst their friends.
I'd work on stressing benefits-benefits-benefits. Knowledge for knowledge's sake is good, knowledge for entertainment is good, knowledge to gratify intellectual curiosity is good... but these are all less powerful than knowledge to solve a specific problem, or knowledge that is necessary to achieve one's goals.
So, perhaps making it very relevant somehow in ways people are already looking for? Nutrition? Sports training? Etc.
Then, of course, you promote your site in various places, submit to Hacker News when you've written a really good one and hope it takes, connect with people... y'know, general traffic building type stuff. I'm not so amazing at this yet, so I'm not the best authority, but definitely think in terms of benefits if you want more people to come to your site.
2. Prestige: Prestige is a funny thing. Prestigious things are prestigious. So a question you might ask is, "How can I establish this a prestigious place?" You can always scratch and claw slowly with good content, like how Eliezer Yudkowsky and Robin Hanson built Overcoming Bias.
At the same time, things like a solidly branded and elegant URL/domain name, custom/pretty design, other indicators of credibility that people traditionally look for might help.
The more you've got traffic and prestige, the more someone is likely to want to create content there in order to get the... well, the traffic and prestige. Most people (sadly) don't pursue knowledge for its own sake, and instead are more interested in benefits and solutions to problems... if you can wrap your knowledge and explorations in a a wrapping of benefits/problemsolving, that would help.
Maybe I could do a bit, if you're interested. Do you have any submission guidelines? I think it'd be fun to do, let me know if that appeals to you.
I think it's a cool thing to do, and it'd be nice to see the project thrive. Regards from Kuala Lumpur,