Buddhism: What is This Ancient Religion?

Today, Buddhism is divided primarily into three traditions:
Theravada - practiced mainly in certain parts of South Asia (mostly Sri Lanka) and Southeast Asia
Mahayana - practiced predominantly in East Asia
Vajrayana - distinct school within Mahayana, practiced in Tibet and Mongolia, and surrounding regions.

History

Śãkyamuni was raised as a Hindu. His parents assumed that he would succeed his father later in his life but were concerned about a prophecy that astrologers gave at the time of his birth. They predicted that he would become either a universal monarch or a monk who would be a great religious teacher. His parents raised him in a state of luxury in the hope that he would become attached to earthly things and to pleasure and make it less likely that he choose the religious life.

At the age of 16, he was married to his wife. When he was 29, his wife had a son. Shortly after his son's birth, some sources say he had four visions. During the first vision he was deeply disturbed by seeing an elderly, frail man. On the second, he saw an emaciated man suffering from an advanced disease. On the third, he spotted a grieving family carrying the corpse of one of their own to cremation. He reflected upon the suffering brought about by old age, illness and death. His fourth vision, he saw a religious mendicant who led a reclusive life of meditation, and was calm and serene. The four encounters motivated him to follow the path of the mendicant and find a spiritual solution to the problems brought about by human suffering.

He left his wife, child, luxurious lifestyle, and future role as a leader of his people in order to seek truth.

Beliefs

Most Buddhists
accept the Buddha as their teacher.
accept the Middle Way, Dependent origination, the Four Noble Truths and the Noble Eightfold Path.
accept that both the members of the laity and of the Sangha can pursue the path toward enlightenment.
accept three types of Buddha and consider Buddhahood to be the highest attainment.

The Four Noble Truths

Suffering: Birth is suffering, aging is suffering, illness is suffering, death is suffering; separation from what is pleasing is suffering; not to get what one wants is suffering
The cause of suffering: Desire
The cessation of suffering: The cessation of desire.
The way leading to the cessation of suffering: The Noble Eightfold Path
According to the scriptures, the Four Noble Truths were the topic of the first sermon given by the Buddha after his enlightenment.

What is the Eightfold Path?
Right Viewpoint - Realizing the Four Noble Truths
Right Intention - Commitment to mental and ethical growth
Right Speech - One speaks in a non hurtful, not exaggerated, truthful way
Right Actions - Wholesome action, avoiding action that would do harm
Right Livelihood
Right Effort - One makes an effort to improve
Right Mindfulness - Mental ability to see things for what they are
Right Meditation

How many people are Buddhists?
About 400 million. It is the fourth largest religion in the world.

How do they feel about current issues?
Buddhism doesn't say anything in particular about abortion.
No consensus exists within Buddhism about gay and lesbian relationships.
Buddha preached non-violence and peace as a universal message.

Why do the monks wear orange or yellow robes?
According to buddhanet.net:
When the ancient Indians looked into the jungle they could always tell which leaves were about to drop from the tree, because they were either yellow, orange or brown. Consequently, in India, yellow became the colour of renunciation. Monks and nuns robes are yellow so they can act as a constant reminder of the importance of not clinging, of letting go, of giving up.

Are buddhists supposed to be vegetarian?
Not necessarily. The Buddha was not a vegetarian. He did not teach his disciples to be vegetarians.

How do you become a Buddhist?
According to buddhanet.net:
Taking Refuge in the Dhamma means understanding the Four Noble Truths and basing one's life on the Noble Eightfold Path. Taking Refuge in the Sangha means looking for support, inspiration and guidance from all who walk the Noble Eightfold Path. Doing this one becomes a Buddhist and thus takes the first step on the path towards Nirvana.