I know a lot of people say they want to wait until they get married/find the right guy, but this can lead to heaps of problems afterwards.
eg. you have a girl who's 17, her friends are all having sex n having a good time n she wants to wait until she finds the right guy or gets married. 7 years down the track she meets this nice guy, spends 14 months with him and decides to marry him. After they get married, she decides to have sex with him. The next few years go by nicely, but then the girl starts to wonder what it would have been like to be with someone else.. this can lead to all sorts of problems (resentment, unfaithfulness etc..).
The idea isnt to go out and fuck everyone you meet that wants to get in your pants, but it's also a good idea to get a bit of variety while you're young, so that when you settle down you'll know for sure you're with the right person.