Sikh philosophy - Prohibited behavior (Wikipedia)

1. Non-logical behavior: Superstitions, or rituals which have no meaning, such as pilgrimages, fasting and bathing in rivers, gambling, worship of graves, idols or pictures, and compulsory wearing of the veil for women, are prohibited.
2. Material obsession: ("Maya") Accumulation of materials has no meaning in Sikhism. Wealth such as gold, portfolio, stocks, commodities, properties, et cetera, will all be left here on Earth when you depart. Do not get attached to them.
3. Sacrifice of creatures: Sati – Widows throwing themselves in the funeral pyre of their husbands, the act of slaughtering lambs and calves to celebrate holy occasions
4. Non-family oriented living: A Sikh is encouraged not to live as a recluse, beggar, monk, nun, celibate, or in any similar vein.
5. Worthless talk: Bragging, gossip and lying are not permitted.
6. Intoxication: The consumption of alcohol, drugs, tobacco, or other intoxicants is prohibited.
7. No priestly class: Sikhs do not have to depend on a priest for any of the functions that need to be performed.
8. Eating meat killed in a ritualistic manner (Kutha meat): Sikhs are strictly prohibited from eating meat killed in a ritualistic manner (such as halal or kosher, known as Kutha meat^[1] ), or any meat where langar is served.^[2] In some small Sikh Sects, i.e. Akhand Kirtani Jatha eating any meat is believed to be forbidden, but this is not a universally held belief.^[3] The meat eaten by Sikhs is known as Jhatka meat.
9. Having premarital or extramarital sexual relations^[4][5][6][7]

^{Source: http://en.wikipedia.org/wiki/Sikh_philosophy}

Sikh philosophy - Underlying values (Wikipedia)

The Sikhs must believe in the following values:

1. Equality: All humans are equal before God – No discrimination is allowed on the basis of caste, race, gender, creed, origin, color, education, status, wealth, et cetera. The principles of universal equality and brotherhood are important pillars of Sikhism.
2. Personal right: Every person has a right to life but this right is restricted and has attached certain duties – simple living is essential. A Sikh is expected to rise early, meditate and pray, consume simple food, perform an honest day's work, carry out duties for his or her family, enjoy life and always be positive, be charitable and support the needy, et cetera.
3. Actions count: Salvation is obtained by one’s actions^{[citation needed]} – good deeds, remembrance of God – Naam Simran, Kirtan.
4. Living a family life: Encouraged to live as a family unit to provide and nurture children for the perpetual benefit of creation (as opposed to sannyasa or living as a monk, which was, and remains, a common spiritual practice in India.)
5. Sharing: It is encouraged to share and give to charity 10 percent of one’s net earnings.
6. Accept God’s will: Develop your personality so that you recognise happy events and miserable events as one – the will of God causes them.
7. The four truths of life: Truth, contentment, contemplation and Naam (in the name of God).

Source: http://en.wikipedia.org/wiki/Sikh_philosophy