These are the Five Moral Precepts of Buddhism:
- to abstain from killing living beings
- to abstain from taking things not given
- to abstain from sexual misconduct
- to abstain from false speech
- to abstain from intoxicating drinks and drugs causing heedlessness
The drugs causing heedlessness is often translated as mind-altering drugs.
The Five Precepts represent the minimum standard of morality (sila) as basis of a decent life.
They are not commandments by a deity, but precepts that most Buddhists voluntarily undertake to live by. If you wish to formally undertake the Five Precepts, simply say (and mean it):
- I undertake to observe the precept to abstain from killing living beings.
- I undertake to observe the precept to abstain from taking things not given.
- I undertake to observe the precept to abstain from sexual misconduct.
- I undertake to observe the precept to abstain from false speech.
- I undertake to observe the precept to abstain from intoxicating drinks and drugs causing heedlessness.
If you have a teacher, or go to a temple, vihara, Zen center (or similar), ask him/them for the particular translation used by him/them.
The above translation is by Nyanatiloka as published in The Word of the Buddha. I have used that particular translation because its Copyright allows for free distribution.
Additional precepts exist: Buddhist monks undertake Ten Precepts. The first five are the same as the Five Precepts. The additional five seem to vary by Buddhist sect slightly.
Lay Buddhists generally undertake the Five Precepts, though it is not uncommon to undertake one or more additional precepts from the Ten. | 
