1. they are a large, influential faith in the world
2. they are totally awesome
i'll get to that second point in a bit, but first let's lay down the basics. sikhs follow the teachings of ten gurus who lived from 1469-1708. the one you really need to know is Guru Nanak Dev - he got the whole thing rolling and the whole religion is really based on his teachings. the other nine gurus are each considered to have his spirit though (like the flame of one candle lighting the next) so as they added to and expanded his teachings they became canon. this is not unlike the star wars novelizations by timothy zahn, which many fans consider to carry on the tonality, scope and adventure of the original franchise. but i digress.
the most basic tenant is that there is one God and it is timeless, boundless, sightless, completely powerful and, insofar as we can understand it, the whole of the universe. "God is everywhere for the awakened mind" is one way the Sikh's think about this. a fundamental idea is that God can never be fully know but _aspects_ of God are knowable. those aspects include the knowledge that God wants us to Share with Each Other, Have an Optimistic View, Protect Weak and Innocent Creatures (especially humans), and Vigorously Participate in Giving Charity. pretty standard monotheistic stuff, but these guys take it a step further.
they believe in reincarnation, but not in any kind of heaven or hell. one sikh i spoke to in college put it this way: "heaven is the joy on the face of a child, and the happiness that can live in the human heart. hell is the pain we inflict upon each other, the wars we wage and the destruction we cause." they do however believe that with proper, intense meditation, a man can overcome the illusion of the world (maya - a term borrowed from hinduism) and come to conquer the Five Really Bad Hang Ups: ego, anger, greed, attachment and lust. When this is done, one can become enlightened, get to know those knowable bits of God and break the cycle of rebirth by joining with God in perfect union.
their base of operations is this enormous temple called Harmandir Sahib - colloquially referred to as the Golden Temple. it is a seriously impressive structure and one i would love to see when we visit india. unfortunately it's really close to pakistan so it's probably a no-go. nevertheless, it is a giant palace made of gold where Sikh's regularly gather to read some scripture, shoot the breeze and sip some garam chai (more on this another time).
the Sikhs had their own Empire for a while, standing in opposition to the Moghul Empire (1556-1707). they were amazing warriors and brilliant scholars. the Sikh empire is still recognized as being one of the most tolerant and pluralistic, with Muslims, Hindus, Christians and Jews being allowed to move and worship freely as well as hold high office. when the Raj finally beat them, he outlawed their martial arts, Shaster Vidiya, but it's stayed alive. the last remaining master of the "Science of Arms" keeps a school in England where he passes on the training. and just like every completely awesome warrior band from the numerous fantasy paperbacks that liter my bookshelf, there is an elite unit with a sweet name - The Akali Nihangs - the blue turbaned elite fighter force of the Sikh Empire.
each baptized sikh comes with kung-fu grip and five action-accessories: kes (growing your hair into an awesome heavy-metal mane of manliness), kangha (a sweet comb to maintain said dudely locks), kara (an iron bracelet), kirpan (a KNIFE) and kaccha (super underwear). seriously though, each of these serves a special purpose:
- kes - a sikh is not allowed to cut their hair. this includes shaving their beards (but they can trim them, see below). they wear large turbans wrapped up around their heads to keep all their hair in when they're out and about (also, they look rather stylish --> boom Boom BooM BOOM). the reason for doing this is that it is considered unnatural to cut hair - if God wanted it short, he wouldn't make it grow. thus not cutting one's hair is an act of submission to God's will (and handsome to boot - just ask my girlfriend) more importantly, though, it identifies a Sikh to all the world. As Guru Singh wrote "..How can he hide himself with hair and turban on his head and with a flowing beard?"
- kangha - the comb reminds the Sikh to be hygienic, disciplined and for goodness sake to wash behind one's ears. this is both a practical implement to facilitate kes, and a token of one's obedience to staying positive and healthy, keeps the turban in place (yes, really) and, just like my seltsen blue lightly medicated shampoo and condition, "keeps hair healthy, clean, shining and tangle-free."
- kara - the iron braclet is to remind a Sikh to use his or her hands for good stuff and not for bad. that's pretty much it, actually. it reminds the sikh to be helpful, kind and giving.
- kirpan - believe it or not, the knife is worn to further the sikh idea of non-violence. each sikh is commanded to carry the blade at all times (making airline flying difficult for them) in order to defend the helpless and weak, fight injustice and to prevent violence. Sikhs were awesome warriors but they truly believed that if you were strong, smart and skillful, you would only use violence to stop violence. they really buy this too - sikhs have traditionally been pretty non-violent dudes. from day one their religion opposed the cast system and they had little love of british oppression, extremist violence and any kind of war.
- kaccha - alright, i make fun but this is pretty cool, too. like the kara reminds the sikh of the responsibility in his hands, the kaccha reminds a Sikh to use his (cough, cough / wink, wink) for noble purposes. it's like a big post-it note that sikhs wear so that when they see it they pause and ask themselves, "is what i'm about to do with what's in there going to be glorifying to my God, honorable to my family and just plain decent?"
if beard-growing, turban-wearing, holy underoo-sporting Jedi from india aren't cool to you, then you probably aren't very cool yourself. as the icing on the already well-iced cake that is Sikhism, they get this awesome insignia which incidentally looks alot like the Klingon insignia from star trek: