I'd start out by always being open and trying to gauge how much a child wants or needs to know sexually. Frequently children are offput by their parent's embarassment on the subject. I remember I was and I also remember that my 5 year old step daughter had questions, more about bodily functions/ what tampax machines were for/where babies came from and I told her nicely she should ask her mother, because basically I didnt want to steal a precious mother daughter form her mother. But the little girl tried and came back and asked me again and said her mother got angry with her and she was scared to ask again, so I told her my version, which hopefully was just enough for her age and not too much (having spoken with her dad to check it was ok!)
sexual awakening - I'd say make sure your kids have plenty of private time and space to um occupy themselves without worrying that you are going to walk in. Watch the transformers movie or American Pie (the Dad in that is bloody excellent) and let them know one way or another your old fogey dad or mom is completely cool with masturbation and there is nothing to be ashamed of.
As for sexual partners, I'd really like my kids to wait until they couldnt bear it any longer. After all I had to suffer why shouldnt they? No, seriously I'd not encourage vast sexual experimentation with multiple partners until they had at least their first experience with someone they cared about it. It colours you. I think it might be where I went wrong. I'd like them to have the choice of unpressured sex with someone they have grown to know and care about first .
(BTW I don't have any kids so I could be miles off target.)