Taking care of your skin is a MAJOR part of a teen's hygiene. You will want to wash your face twice a day (no more) with warm water. If you are concerned about acne, you can wash your face with a mild soap made for people with acne. Do not scrub, because it can cause skin irritation. It is also recommended that after cleansing you apply a lotion containing benzoyl peroxide.
I cannot stress enough that your skin needs to be protected from the sun! Tanning causes damage to the skin, eventually leading to wrinkles and increases your risk of skin cancer. Always wear sunscreen with an SPF of at least 15, and if you sweat a lot or go swimming, make sure to reapply every 1 1/2 to 2 hours.
The best way for you to keep clean, however, is to bathe or shower every day. When doing so, make sure to use a mild soap and warm water. This helps wash away bacteria contributing to body odor.
Hair is another big deal. Nobody wants greasy hair, AT ALL. So washing your hair either every day or every other day will certainly help control the oil. Use warm water and a small amount of shampoo to work up a lather. Don't scrub too hard! It won't remove oil any better, and it could damage your scalp/hair.
Now on to shaving- yes, this is for both guys and girls. You can choose between a traditional razor with shaving cream or gel, or an electric razor. If you're using a traditional razor, make sure the blade is new and sharp to avoid nicking yourself. Try to use shaving cream instead of soap since it pulls easier on the skin. Go slow when shaving your legs, armpits, or face since these areas have many curves, and you could cut yourself if you go to fast.
Last but not least, DEODORANT! If you happen to be smelling under your arms, try using a deodorant or antiperspirant. Deodorants just cover up the odor of sweat, while antiperspirants dry it up. They come in sticks, roll-ons, gels, sprays and creams. Make sure to read the directions before applying, because some work better at night while others in the morning.