John Bullitt wrote:I want to become a Buddhist. How do I do that?
It begins with one deceptively simple act: making the inner commitment to "take refuge" in the Triple Gem, to accept the Buddha, Dhamma, and Sangha as your source of spiritual guidance. This act is what makes one nominally "Buddhist." But going for refuge also implies a willingness — if only provisional, at first — to accept the cornerstone of the Buddha's teachings: the law of kamma. According to this universal principle, if you act unskillfully and make poor ethical choices, you are bound to suffer the consequences; if you choose wisely and act in line with the noblest ideals, you stand to benefit accordingly. In other words, your happiness ultimately depends on the quality of your choices and actions; you alone are responsible for your happiness. Your first act after seeking refuge should therefore be to resolve to observe the five precepts — the five basic principles of living that can help prevent you from making grossly unskillful choices. This is where the practice of Buddhism begins.
You don't need a formal public ceremony or "initiation" to make any of this official. There are no equivalents in Buddhism to Christianity's "baptism" or "confirmation" rituals. You don't have to dress differently or wear a badge that says, "I am now a Buddhist." The practice of the Dhamma is a private matter and no one needs to know about it but you. Many Buddhists do, however, find it invaluable to renew their commitment to the Triple Gem and to the precepts from time to time in a more formal way, enlisting the help of a good friend, a respected meditation teacher, or a member of the monastic community (Sangha) as a witness. Administering the refuges and precepts to laypeople is a duty that Buddhist monks are glad to perform.
Many people find it difficult to sustain their commitment to the Dhamma on their own, without the support of like-minded friends and companions. (It can be hard to stick to the precepts if you're surrounded by people who see no harm in telling lies, or in having a secret romantic affair now and then, or in going out drinking all night.) You may have to do a little patient detective work to find this kind of support (see How can I find other people with whom to study Dhamma and practice meditation?, above).
Having taken these first steps, you can proceed along the Buddhist path in your own way and at your own pace. Although you can learn a great deal about Dhamma on your own, your understanding will grow by leaps and bounds once you find a good teacher — someone whom you trust and respect, who keeps to the precepts, and who understands the Dhamma and can communicate it clearly. Other aids to progress in understanding the Dhamma are these: deepening your understanding of the precepts; studying the suttas; getting to know monks or nuns (the Sangha) and becoming acquainted with their traditions; developing a keen, discerning ear that can recognize which of today's popular spiritual teachings actually ring true to what the Buddha taught;6 and learning meditation. How you proceed is entirely up to you, but the bottom line is this: learn what the Buddha taught and put it into practice in your life as best you can.
If you ever decide that the Buddha's teachings aren't for you, you are free to walk away at any time and find your own way. There is no ceremony for renouncing the Buddha's teachings. Just remember: your happiness is in your own hands.
From: Frequently Asked Questions About Buddhism
by John Bullitt