Buddha taught his newfound truths (dharma) to others. In his teaching he said, "Seek salvation only in the truth; for assistance look to none but yourself". So the primary belief of Buddhism is that enlightenment comes not from a god, but from personal effort and development in proper thinking and good deeds.
Buddhism also believes that life is not a linear order of chronological events, as it is perceived in the West. Life is a self-repeating cycle of life and death, and human history is of little importance. Our eternal selves wander from life to life through eternal rebirths (samsa) and suffer the consequences (karma) of actions in life. By being good, our lives (spirit) will have goodness reflected back upon us. By being evil, our lives will be reflected with despair.
Since Nirvana is may be an unattainable goal, in this lifetime, the goal for most Buddhists is to be a harmonious, benevolent and a positively contributing influence on society. Though we may not achieve enlightenment in this lifetime, we should strive for knowledge and understanding so that we may achieve Nirvana in our future life. With a Taoist influence, we are taught to understand that it is not the destination, but the journey itself, that is of greater importance.
Rituals, good works and study are important ways to help one on their journey to achieve Nirvana, but ultimately everyone must use their mind and meditation to achieve "enlightenment".
Since the death of the Buddha, there have bloomed many different schools of Buddhism. Buddhism is not one religion, but many different and diverse schools of thought, with the concepts of Nirvana and Karma being fairly constant.
In Zen Buddhism we are taught imponderable riddles such as "What is the sound of one hand clapping?" or "What do we find where there is nothing?". Through the contemplation of these riddles we will help ourselves realize Nirvana.
Zen is often taught through the study of a discipline, Archery, Swordsmanship, Flower Arranging, Calligraphy. Through studying the discipline, and learning from the failures as well as the successes, the Master will be aide the student in his own mastery of Zen as well as the discipline. So the discipline becomes an aide to learning Zen, not the other way around as many westerners believe.
Meditation is seen throughout the Martial Arts. Most Martial Arts classes begin and end with some form of meditation. There are many variations on meditation. This is all because of the influence of Buddhism.