I have two girls just hitting the teen years (13 and 12) and we are just starting to have to consider these questions seriously. We do not allow our children to watch porn and the porn in our house is locked up, mainly because we are very advanced kinky people and we want them to develop their own kinks naturally. Our girls are very innocent still and homeschooled so they aren't dealing with the same issues as some of their peers. We aren't intentionally keeping them sheltered; hell they know I sleep with both their Dad and their brother's father they just don't know what that entails, nor are they interested. We discuss sex openly with and around them in both mildly ribald and medical terms. I don't think any of the three of us would hide what we've done in the past should the girls ever ask, we aren't ashamed of what made us who we are or of what we've done. My sex life in detail is none of their business, nor will it ever be their business. I don't see a time where, as adult women, it will be my business what they are doing unless it threatens their lives or the lives of their children...and it would have to be pretty bad for me to get involved. Now if I suspected abuse then a frank discussion would happen but it still isn't my business if they tell me to butt out. I pray to God and Goddess that they have learned enough to be able to pick a partner or partners that wouldn't hurt them and I would fight like a scalded cat for each of them (if they were older and I'm no longer legally able to stop them...before that time I'd castrate anyone who would hurt them sexually male or female) but as adult women they have to be willing to fight for themselves equally hard for it to work. I hate that this is true. As teens I have the right to know if they are having sex, and if they are practicing safer sex practices. As teens they are still under my care and their well being is still my responsibility. Since they know I take my responsibilities very seriously they are prepared for me to inquire. I also reserve the right to be nosey about drugs, alcohol or other destructive acts. My oldest has the worst period pain I have ever seen and I think we are going to need to have her tested for PCOS or placed on BC to help her out. If either of them wanted to go on birthcontrol to reduce the risk of pregnancy then I would probably not have a problem with it as long as they understood that BC isn't 100% and won't stop you from contracting an STD. To me it would indicate they are responsible enough to be concerned about their health and trust me enough to talk to me about it.
My kids are homeschooled but I think that with some discussion about what to do if they feel pressured or have people enguaging in risky behavior around them I could trust them at an after party. I'd worry and be up all night but I hope I could trust them. At 13 my daughter isn't ready for a boyfriend emotionally, and at 12 my other daughter thinks boyfriends are too much trouble. I have met 13 year olds who were emotionally ready and I will have to judge at the appropriate time whether it's a good thing.
If either of them wanted a vibrator I'd first have a serious talk about their bodies, discuss why they want a vibe and then we'd discuss proper body safe materials and care/upkeep of said toy. I don't have a problem with them using a toy, I used them at a young age. Right now they aren't interested so I leave it up to them while letting them know my toys are off limits, I don't share.
We have a unique situation since both my daughter's parents have other partners at any given time (mine is a permanent fixture but he isn't poly, he's more of a swinger) so they hear make out advice inadvertantly though we keep it PG around them it leaks occasionally. To be fair even with my parents, Grand parents and aunts/uncles being monogamous we often heard ribald advice and comments growing up so it's no different. If they asked for my advice I'd certainly try to help but I wouldn't offer it unsolicited.
I don't care what underwear my girls wear except when they are out in public with me...then I would prefer that they wear underwear and that I not see them. Other than that I don't care, they get their choice in that.
The other question I get all the time is do I think I will be sickened if my children become raving sex lunatics...ok that's generally not how it's phrased but it's what people mean. The answer I have to give them is: As long as they are taking care to remain healthy in mind and body what they do in their sex lives is their concern and I love them even if they ARE raving sex lunatics. I will reserve the right to take out a huge life insurance policy if they are into highly risky behavior though...

*Nods* My son is way more trouble and exasperation than my girls were and he's only 8 months old! His father and I are just waiting for the real fun to begin.

OMG that's child abuse..it's called 'prurient interest' and it's none of your business unless the child has a question about her orgasms or sexual positions. Just ick...

I agree P'Gell you have to remember what it was like feeling all scared, excited and squicked that you were somehow weird and freaky. Then you have to be available and open...mostly it's just waiting for the appropriate moment and answering every question honestly.

For the love of God and little green apples NEVER tell your daughter that she'd better not bring a bastard to your home or you'll throw her out and disown her (or threaten physical violence). That was what my father did and it lead to a D&C for me alone and scared out of my mind at 17. I had a spontaneous miscarriage that had complications and I couldn't talk to my parents cause they threatened to hurt Sigel and me physically if I was pregnant. This is one of the most painful things I have had to go through and caused irrepairable damage to the relationship between myself and my parents. (As it is I still haven't allowed them near my son because I am afraid of the whole bastard label being pinned to him. His father has accepted him as legitimate and has given him his name but I am still afraid.) A baby is not a life ruining event...it's a blessed event regardless of the marital status of it's parents. It's something that can be avoided and SHOULD be planned but it isn't the end of the world, it's the beginning. It's much more difficult to raise a child when you are young and not able to care for yourself yet, but it doesn't make you a permanent disgrace. These are the lessons I want my girls (and son) to understand. PLAN to have time to PLAN for a baby, don't take needless risks. This could have been avoided in my case with BC. I asked for it but I was told I didn't need it and if I didn't have it then it would guarrantee I didn't have sex....mmmhmmmm real sucessful strategy.