I'm 13, and I thought it was a little. . ."iffy". I think it all depends on maturity, and how your kid is able to handle issues of this movie. I personally don't recall drugs or alcohol (though I may have just not been paying attention), but sex is definatly an issue, as well as at the same time a good opener for "the talk" or atleast a good topic for young girls about how some guys may look at them.
There are some scenes that truly got me wondering "Ok, so much for a family movie." like where several girls are all begging for sex with one male, or when one of the perverted boys grabs a handful of condoms and looks at his girlfriend. Or where a teenage girl gets Zach's character in a bedroom and is lunging at him for sex.
Also Zach's friend has a girlfriend of which sex comes up, it doesn't show anything, but at the end of their date they discuss whose house they'll go to, and things like that.
What I mean by good role models is when Zach gets confronted with these sexual issues (because inside he's a grown man), he knows what happens and tries to avoid them, as well as lean the distraught teenagers towards realizing the consequences BEFORE it happens.
So if you think you're child is ready, as well as YOU; the parent are ready to talk about these issues, then I say 13-14 and up, but be very certain if you are showing you're 13 year old. You may want to pause the movie and explain how this relates to real life and how they need to be careful, I've seen young teens (that's right, 13-14), who think this is what always happens in high school, that's as you say; "the norm", and they use that as guidelines for their actions.
Overall the movie is heartfelt and funny. But that doesn't always make it appropriate.
(As for violence, I believe one fight scene, that from what I recall Zach was in for his good reasons, not too much child explaining there.)
(And as for swearing; yes, there is some. But alot of teenagers and young teens as well DO swear alot. I'm definatly not saying it's good, but I'm saying your child should begin getting used to it, if they are atleast 13, but you should also talk to them about how NOT to swear, and to not give into that temptation. I, like I said, am 13, and almost all my classmates swear some of the time, but I remember there are better words for every one of those, and I tune it out, as well as try and ease them towards swearing less, to where at least they don't swear around me, and you should urge your child to do the same. They need to build a "no drugs, no sex, no language" reputation with their classmates, and they should be slightly more behaved around your child, (but results may vary))