Simran: Always remember God
Seva: Do good things for the sake of being good. Feeding the hungry, donating to charity, etc is seva. Many Sikhs consider my wife's advice to Sikhs about how to care for the "joora" [the knot long-haired Sikhs keep to put in their turban] to stop from damaging their hair or losing any, as seva, for example.
Follow the Three Pillars of Sikhism
Naam Japo: Repetition of the Naam (Name of the Lord)
Kirat Karo: Honest living. Earn your keep from the sweat of your brow, not from begging.
Vand Chakko: Share your fruits with others.
Destroy the Five Thieves:
Kaam: Lust
Krodh: Anger
Lobh: Greediness
Moh: Attachment [to worldly things. Like in Buddhism]
Ahankar: Egotism
Replace the Five Thieves with the Five Virtues:
Sat: Truthfulness
Santokh: Contentment
Daya: Compassion
Nirmata: Humility
Pyare: Love
Additionally, one must:
- Believe in the One God who is the source of all.
- See everyone as equal, regardless of race, caste, sex, creed, and sexuality.
- Defend the innocent; a Sikh cannot just walk past as someone is mugged, for example. Whilst Sikhism does prohibit violence, it does hold the view that sometimes it is necessary to fight back for the sake of peace. The general idea from my perspective is "Don't go around starting on people, but if someone attacks you, your family, or an innocent person, it is your duty to kick the living **** out of him."
Sikhs are prohibited from
- Intoxication: no booze, drugs, or smokes are allowed.
- Adultery: don't screw around with other people
- Superstition: no icon-worship, veil worship, grave worship, veiling women, circumcision, fasting for spiritual purposes, or bathing in sacred rivers.
- Materialism: You can't take it with you.
- Animal sacrifice and sati
- Non-family living (as a beggar, hermit, etc)
- Bragging, gossiping, etc
- Following castes. Sikhism does not have priests. The closest thing is a "Granthi", one who cares for the Guru Granth Sahib, of which any Sikh may do regardless of race, sex or caste.
- Eating ritualistically killed meat [no halal or kosher], called kutha meat. Many take it to mean "no meat", though. All food in a langar, a Sikh food hall, is vegetarian.
When one takes Amrit (baptism) and becomes initiated into the Khalsa (Army of the Guru), or decides to vow not to cut their hair, then that person is thusly prohibited from cutting their hair. Many Sikhs out there are what are called Sehajdhari Sikhs---literally, "Slow adopters". They are Sikhs who cut their hair. Some Sikhs do not believe those who cut their hair to be Sikhs, but I've seen many shaved Sikhs and I've never seen them treated badly. If one is not ready for kesh (unshorn hair), then what good would forcing them to keep it do. I feel that when others say "Tum sikhi nahi" (You are not a Sikh) because of kesh, they are influenced too much by maya--illusion and attachment to the material world, and so ignore them. After all, it says in the Guru Granth Sahib:
ਕਬੀਰ ਪ੍ਰੀਤਿ ਇਕ ਸਿਉ ਕੀਏ ਆਨ ਦੁਬਿਧਾ ਜਾਇ ॥
ਭਾਵੈ ਲਾਂਬੇ ਕੇਸ ਕਰੁ ਭਾਵੈ ਘਰਰਿ ਮੁਡਾਇ ॥
Kabīr parīt ik sio kīe ān dubidhā jāe
bhāvai lā'nbe kesh kar bhāvai gharar mudāe
Kabeer, when you are in love with the One Lord, duality and alienation depart.
You may have long hair, or you may shave your head bald.
- Sri Guru Granth Sahib, page 1365.
A Sikh is encouraged to wake up early morning, bathe/shower, and then to chant and meditate on God's name. Naturally, a Sikh should, of course, follow the ten human gurus and see the Guru Granth Sahib as their guru.