Reddit had a moment this week.

Sure, Reddit was already the unofficial "front page of the Internet," the soul of all things meme, the secret sauce behind BuzzFeed's viral posts, a breaking news curator and a Q&A forum for journalists, celebrities, newsmakers.

The Reddit alien mascot.

But then President Obama did a surprise Q&A appearance Wednesday that nearly crashed servers and drew almost 23,000 comments and questions.

Obama didn't bestow legitimacy upon Reddit -- with nearly 40 million visitors and 3.2 billion pageviews a month, it already had that. But the visit from a sitting president certainly says something about its increasingly mainstream relevance.

The Verge's Adrianne Jeffries likens it to another watershed moment in presidential pop culture from 1994:

Remember when Bill Clinton answered the "boxers or briefs" question during an MTV "Rock the Vote" forum and young voters thought it was the coolest thing ever? Well, Reddit is the new MTV.

So it's time for journalists to understand Reddit and the role it plays not only in culture, but in specific news events. A Virginia Tech sophomore shared live updates on Reddit "as SWAT members swept the VT campus" during a 2011 shooting. Witnesses and other Aurora residents covered the theater shooting last month.

But the tricky thing about Reddit, for newcomers, is that it's really not like anything else out there. Here's a basic guide.

The structure: Reddit consists of a bunch of "subreddits," or topic sections. The most popular stuff bubbles up to the front page, but each post starts and lives on a specific subreddit. Every post, and every comment on every post, can be upvoted or downvoted by each user. Votes are how the community determines the best content, which rises to the top.

Don't spam with your own links: This is especially tricky for journalists, who are conditioned to blasting links to their work across Twitter and Facebook. Reddit discourages users from posting self-promotional links to their own work, at least in excess. Tolerance for this varies on different subreddits, but several websites including The Atlantic and Businessweek had their links temporarily banned as punishment for that behavior. So be cautious. Ideally you've built enough readership and engagement around your journalism that other redditors will be posting your links on their own.

Definitions: Like many online communities, Reddit has developed its own shorthand. AMA, the type of post Obama did, stands for "Ask Me Anything." It's an open Q&A thread where one notable person answers questions from everyone else. TIL is short for "Today I Learned..." TIL usually precedes a specific surprising fact. Both AMAs and TILs could be occasional sources of story ideas for journalists.

Not everything there is journalism: And that's OK. Reddit is a social news site (a play on "read it"), but its definition of "news" is much broader than what most journalists are used to. Cat pictures, memes and animated GIFs will make the front page right next to serious political or science news. Don't make the mistake of thinking one discounts the other. There's a lot of valuable information in the Reddit community, you just have to find the parts that are right for you.

Listen before you speak: If you're new to Reddit, spend some time lurking and listening before you jump in and start posting. You'll get to know the habits and customs, and some of the many, many inside jokes. Then you can flex your memeology, like Obama did yesterday with his own "Not Bad" reference.

So, get you started. But be warned, you may find it hard to stop using Reddit and get back to work.

Related: Journalists who have done AMAs include New York Magazine's Frank Rich, Huffington Post's Sam Stein and Washington Post's Ezra Klein.