1) "The hymen (also called maidenhead) is a fold of mucous membrane which surrounds or partially covers the external vaginal opening." "The hymen has no known anatomical function. In societies which value chastity, the greatest significance of the hymen is a traditional belief that an intact hymen indicates a state of intact virginity. However, it is not possible to confirm that a woman or post-pubescent girl is not a virgin by examining the hymen. In cases of suspected rape or sexual abuse, a detailed examination of the hymen may be carried out; however, the condition of the hymen alone is often inconclusive or open to misinterpretation, especially if the patient has reached puberty." "The hymen may be damaged by playing sports, using tampons, pelvic examinations or even straddle injuries." "It is common to damage the hymen through physical activities such as horseback riding and biking. In fact, biking is the most common way to rupture the hymen through physical activity. Contrary to popular belief, the breaking of the hymen is not necessarily an indicator of the loss of virginity." Source and further information: http://en.wikipedia.org/wiki/Hymen 2) "One thing to understand is that one unfortunate aspect of defining virginity by the state of the hymen is that it just isn't accurate, in terms of the state of the hymen truly representing if a woman has been sexually active or not. Even without sexual activity -- whether that activity is with a partner, or via masturbation -- most women's hymens will still gradually erode on their own over time, and by the time most women are through with puberty, the hymen will already be only partially intact. That happens due to estrogens (hormones), normal vaginal discharges, menstruation, general physical activity and -- yes -- also due to masturbation, IF you're really having contact with the vaginal opening or vagina. But even if you were not masturbating, it is likely your hymen would still be slowly wearing away on its own. So, in that way, if virginity in your community is proven by the state of the hymen, it really doesn't matter if you masturbate or not, because you still can't control all those other things that wear the hymen away, if you follow. I know that seems to leave you in a sort of lose-lose place, but in so many ways, virginity requirements -- especially when they're not based on not having partners, but on anatomical issues -- are lose-lose for women, and there's just no sugarcoating that, or making it better, when you're in a culture or situation where there's no changing those requirements or ideals." Source and further information: http://www.scarleteen.com/article/advice/virginity_standards_and_masturbation

its placed at the beginning of the vaginal opening. and yes a girl can break her hymen by masturbating or insertion of her fingers. it usually is quite painful, and u can bleed, but if you dont thats normal, as some females dont bleed at all. As the vaginal area is very sensitive and tender, if too much pressure is applied a female can feel uncomfortable and bleed a little for a couple of days. This is all fine as the body is just getting used to bodily changes. Just be careful as you dont want to scratch or be too rough.

A picture is worth a thousand words, eh?