From what I have, Sikhism is a bridge religion between Islam and Hinduism, some sort of amalgam of the two faiths. Islamic portions are fairly low in relative importance though. Guru Nanak originated the religion, and the religion strove to reconcile the differences between Hindus and Muslims.
Some of the Sikh beliefs:
There is only one God, True Name.
All faiths worship the one God, just with differing names given him. So, everyone worships True Name through varying monikers, if the word can be applied to names given by another.
It is thus wrong for any religion to have rivalry or strife with another, since they all worship the same deity.
The reconciliatory belief was held through Guru Arjun.
Arjun was imprisoned, tortured and mistreated by the Muslim ruler of the area of India where he lived. Before his death, he commanded his son to rule the Sikhs fully armed, to defend the faith. So, following this, the Sikhs would defend their right to believe as they would.
One day during a festival, Guru Gobind was in his tent. As the Celebration reached a high level of activity, Gobind came out of his tent and asked for a follower that would give his head for the religion. One came forward, Guru Gobind took him into the tent and came out with a bloody sword asking for another volunteer. This continued for five volunteers. After five volunteers, Guru Gobind opened the tent to reveal the five men alive with five decapitated goats. Gobind then named the five the first members of the Khalsa, "The Pure Ones".
The Khalsa are not allowed to worship any lesser incarnation of the True Name. The five were from different castes and as such the rights performed at the festival destroyed the caste system for Sikhs.
Rules for the Khalsa:
[list=1][*]Baptism uses amrit stirred with a double-edged sword.
[*]Wherever there are five members of the Khalsa there is the whole khalsa.
[*]Kesh - Uncut hair and beard, symbolizing spirituality and respect for natural laws
Kangha - a comb, symbolizing control of mind and body
Kachh - short underwear, symbolizing that one is moral and controlled
Kara - steel bracelet, symbolizing the oneness of God and the unity of the individual with God and all mankind
Kirpan - a short dagger, symbolizing dignity, self-defense and the just use of power
[*]No distinction between members based on social or economic factors
[*]Must revere the Granth (Sikh holy book) and they must travel to Amritsar (an area in Northwest India) to dip in the Pool of Immortality surrounding the Golden Temple
[*]must be prepared for war in defense of the faith
[*]money must be honestly earned and a tithe must be given to worthy causes
[*]Sikhs should not practice either Islam or Hinduism
[*]All relatives of a member of the Khalsa are considered relatives of all Khalsa
[*]No gambling, theft or use of tobacco or alcohol
[*]No intermarriage with any that break the laws of the Khalsa
[*]Greetings to be used upon meeting another member of the Khalsa: "The Khalsa is the Lord's" and "Victory is the Lord's"
[*]Violation of the rules results in a need for repentance, a fine, a promise to not break the rule again, and re-baptism[/list]
Goal in life for the Sikh - to become one with God and escape the reincarnation cycle.
True Name is the eternal Guru, but the spokesmen of True Name are known as Gurus as well.
Meditation is the way to God.
There is what I gleaned from my texts in the past few hours, I probably won't do much more research given limited time available for such.