I suggest Truly Part of You, as it has the highest ratio of insight to length. My only concern is that the jargon is uses may violate your first criterion. However, the jargon is explained sufficiently where it's used in TPoY; it's only a problem if seeing such terms is intimidating to your friend. For example, there's the passage
So, McDermott says, "A good test for the disciplined programmer is to try using gensyms in key places and see if he still admires his system. For example, if STATE-OF-MIND is renamed G1073..." then we would have IS-A(HAPPINESS, G1073) "which looks much more dubious."
I didn't know about gensyms at the time (and still don't have mastery of the concept), but you can see that in context it makes the point clear.
I've recently been trying to introduce some of my friends to less wrong. As a starting point I've linked them to HP:MOR and 'Three worlds collide' on the basis that they are both entertaining and accessible. But I'm not sure where to go next. Sending them to a main index page would likely be overwhelming, so could you suggest some sample articles to give them a general flavour of less wrong and envourage them to read more?
Qualities for such articles would probably include being:
What would you suggest?
[As I'm still a relative novice myself, apologies if a similar discussion has been had in the past and I haven't stumbled across it.]