Best thing I heard in sex ed was a health teacher telling us "the way to put on a condom so it's 100% effective all the time." She originally said it in response to a male student who was repeatedly a jackass during class, inappropriate and disrespectful, etc.

Evidently if you roll on the condom as usual, then you grab one of the edges, and pull it reeeeeeeally really tight and let go so it SNAPS back into place, it's always going to be 100% effective. You're really not going to want to do anything after that...

This is the same teacher who started off the lesson on female anatomy by having the class shout "vagina" and "clitoris" in unison so we could all get the giggles out of our system early and she could proceed with the lesson.

I still wouldn't say I was completely educated about sex, but I at least got the basics. I agree with KibbleKing up there, that teaching how to SAY and HEAR "no" would be an awesome start. We got an awful lot of lecturing for the girls about how they shouldn't trust guys, at all, ever, and how they have every right to say "no" - but precious little time was spent on talking to the guys about their responsibilities, too. Just a throwaway "control your urges and rape is bad but that should be obvious so let's just move on."