• Avoid killing, directly or indirectly.
• Avoid stealing and taking things without the permission of their owner.
• Avoid sexual contact.
• Avoid lying and deceiving others.
• Avoid toxicants: alcohol, tobacco and drugs (except for medicinal purposes).
• Avoid eating more than one meal that day. The meal is taken before noon, and once one has stopped eating for thirty minutes, the meal is considered finished. At other times of the day one can take light drinks, but not undiluted whole milk or fruit juice with pulp. Avoid eating black foods: meat, eggs, onions, garlic and radishes.
• Avoid sitting on a high, expensive bed or seat with pride. Also avoid sitting on animal skins.
• Avoid wearing jewellery, perfume, and make-up. Avoid singing, dancing or playing music with attachment.

For a precept to be broken completely, four conditions must be present:

• The motivation is a negative attitude such as attachment, anger, etc.
• There is an object of the action, e.g. a being that is killed or an object that is stolen.
• One does the action. If one tells someone else to kill, steal or lie, it is also a transgression.
• The action is completed, e.g. the being dies before oneself or one thinks, "This is mine."

The first time one takes the precepts, it is done from a master. Thereafter, one can do the ceremony before a Buddha image by regarding it as the actual Buddha.

Source: http://buddhism.kalachakranet.org/resources/8_mahayana_precepts.html

Other Resources:

• http://www.thubtenchodron.org/PrayersAndPractices/the_eight_mahayana_precepts_ceremony.html

• http://www.fpmt.org/prayers/8precepts.asp