I use facebook a lot, and I enjoy it. I use it mostly for keeping in touch with family/relatives overseas, and contacts I have professionally (but only those who have become friends in the real world) and contacts I have through my keen interest in music (in the last year, I have added people I have never met, but I communicate with regularly).
What do I post? Music mostly, fave tracks/unusual tracks that I know my friends will enjoy. Photos... none of my kids, or even Mrs F, but ones I've taken of cycling, countryside, etc.
I don't put comments about what I'm having for dinner, moan about my job, or that leak in the bathroom etc. Just stuff I think people will like. And that is largely what most of my friends do, apart from one who appears to be drinking far too much and posting rants from his local pub, which is worrying.
HOWEVER.... I'm amazed by two things.... I count myself as a fairly typical middle-aged, middle class bloke (these days, anyway), reasonably intelligent and able to sort out privacy settings... there are a lot of friends (same demographic as me) who have FB accounts, but spend all their time moaning about it, and saying to me 'blimey, you actually use it? why?' etc etc. So I tell them what I've told you, and then I say simply, look, if you don't like it, don't have an account. Simples.
The second thing that amazes me is the number of peeps (again same demographic as me) who have not worked out their privacy settings. I've seen photos of the children/weddings/barmitzvahs etc etc of 'friends of friends' who I have no connection with. Not stalking them, just sometimes 'click through' just as a test.... a woman who lives locally, who I kind of know, but not friends on FB, has a photo up of herself sunbathing topless in her back yard. I'm sure she'd be shocked if she realised complete strangers could see it.
So three things...
1) If you don't like it, don't use it
2) Sort yer privacy settings out
3) I'm perfect.
[edit: I haven't joined the CC FB either, as then you would know my real name, and I would have to kill you]