I have to guess what features of mine are useful to share, which I've proven to be less than 50% effective at in the past.
Let's see, what features have I seen come in handy ...
The philosophical positions you hold would be good; helps stop people assuming you hold opinions you don't.
Some people might like to know roughly where you are, both in case they need to talk about something that differs between nations or you live near them and they can rope you into attending meetups.
If you have any areas of expertise/qualifications, people who seek knowledge on those topics (for whatever purpose) would know they can ask you and get the mainstream position on things. For example, people with any training in physics will be treated as evidence in debates over the many-worlds interpretation of quantum mechanics. This could be a double-edged sword, though, in theory.
An additional issue is that I'm skilled at being deliberately inflammatory or conciliatory. Good enough that I sometimes do it by accident.
Hmm. Does this conciliatory ability extend to sacrificing your interests? Because if not, it sounds like a handy minor superpower.
A few notes about the site mechanics
A few notes about the community
If English is not your first language, don't let that make you afraid to post or comment. You can get English help on Discussion- or Main-level posts by sending a PM to one of the following users (use the "send message" link on the upper right of their user page). Either put the text of the post in the PM, or just say that you'd like English help and you'll get a response with an email address.
* Normal_Anomaly
* Randaly
* shokwave
* Barry Cotter
A note for theists: you will find the Less Wrong community to be predominantly atheist, though not completely so, and most of us are genuinely respectful of religious people who keep the usual community norms. It's worth saying that we might think religion is off-topic in some places where you think it's on-topic, so be thoughtful about where and how you start explicitly talking about it; some of us are happy to talk about religion, some of us aren't interested. Bear in mind that many of us really, truly have given full consideration to theistic claims and found them to be false, so starting with the most common arguments is pretty likely just to annoy people. Anyhow, it's absolutely OK to mention that you're religious in your welcome post and to invite a discussion there.
A list of some posts that are pretty awesome
I recommend the major sequences to everybody, but I realize how daunting they look at first. So for purposes of immediate gratification, the following posts are particularly interesting/illuminating/provocative and don't require any previous reading:
More suggestions are welcome! Or just check out the top-rated posts from the history of Less Wrong. Most posts at +50 or more are well worth your time.
Welcome to Less Wrong, and we look forward to hearing from you throughout the site!
Note from orthonormal: MBlume and other contributors wrote the original version of this welcome post, and I've edited it a fair bit. If there's anything I should add or update on this post (especially broken links), please send me a private message—I may not notice a comment on the post. Finally, once this gets past 500 comments, anyone is welcome to copy and edit this intro to start the next welcome thread.