Several Options. The best is condoms, hands down- protect from pregnancy and infections! for pregnancy only, pills are great if you can remember to take them. The 'patch' provides similar hormones through the skin for 1 week at a time. The 'ring' provides lower doses of hormones directly into the vagina 3wks at a time, and is easy to insert/remove yourself. Check out: birth control options http://shar.Es/f1zrp.
Contraception Choice. Contraceptive choice is based on several factors. How effective you want the contraceptive, how often do you have sex, do you have any medical problems, how good are you at remembering to take your pills or use the diaphragm, etc. You need to have a serious review of these and other issues to make an informed decision. Choose the one that will work for you :).