Puberty can be divided into roughly 5 stages. Every woman goes through them at her own pace, and the stages overlap, but here they are as a sort of rough guide:
At Stage One (ages 8 to 11), not much is happening on the outside of your body. But inside, you've got it going on. Your ovaries are maturing, and your brain has stimulated the release of hormones that you'll need later for menstrual and baby-making functions.
During Stage Two (ages 8 to 14), noticeable changes are happening. Breasts are developing, with the nipples and surrounding area (a.k.a. the areola) getting darker and growing a little bigger. Your first pubic hairs make their appearance. You'll probably grow taller, and your hips, thighs and derriere may begin to fill out. Don't bug about putting on some pounds: you're supposed to gain weight right now. (Without a certain amount of increased body fat, you won't develop properly.) It's fine. But to lessen the shock, and to keep feeling good about your body, stay active and eat right.
Stage Three (ages 9 to 15) continues these outward changes. Those breasts and pubic hair keep on growing. Height, yup, you're getting that too. Your hormones are kicking in now, causing your vagina to begin producing discharge. It's no biggie, just part of a natural cleansing process, so banish the word "gross" from your vocabulary right now, please.
As you enter Stage Four (ages 10 to 16), your body begins to take on a more mature look. More nipple development, coarser pubic hair (and more of it), plus the debut of underarm hair. The biggest change, though, is happening internally. Your ovaries are growing and may even begin producing eggs. Some girls get their first period.
Finally, in Stage Five (ages 12 to 19), you've reached the end of puberty. Your breasts get to be their full size, your pubic hair is all there, and you've pretty much stopped growing. If you haven't already started your period, it should begin during this stage.
At the end of puberty,when you are 18 or when you become sexually active,you'll probably have your firs gynaecological visit.