founder of Sikhism "Guru Nanak" learned from Muslim Sufis as well as Hindus. It was actually an attempt to find mid path between Islam and Hinduism. Sikhs do not keep idle in their place of worship.
The unity of God, some of their dress codes etc. might be from Guru Nanak's relation with a Muslim saint. He was from Hindu family. It's some mix of Sufi ideas than true Islam.
Sikhism is strictly monotheistic in its belief. This means that God is believed to be the one and sole Reality in the cosmos, meaning that no other being have extra-human power. Sikh Gurus state that God alone is worthy of worship, and the highest end of existence, that is mufti or liberation can come through Devotion to God alone.
Besides its monotheism, Sikhism also emphasizes another philosophical idea, which is known as monism. Monism is the belief the world is only a "vision" or illusion (Maya) and that God is the sole "Continuing Reality" so that selfishness, egoism and hate are meaningless.
If you get onto this site you will everything about similarities abed differences between religions.
http://www.beliefnet.com/Faiths/Sikhism/...
Ill just cut and paste some extra -about Sikhism -
To understand Sikhism you have to understand Hinduism. Hinduism is not Christianity and Islam which are codified religions, and have a book and a prophet. Hinduism has originated from various rituals tribal customs and social life over the centuries. Hinduism has 1000?s of Gods and Goddesses and various diverse thoughts.
Predominant amongst these thoughts is a way of life called Sanatan Dharma which more than 60% of the Hindus follow, and this is generally mistaken as Hinduism, and the other thoughts are treated as offshoots of Hinduism. The real truth is that Hinduism means Sanatan Dharma AND all the other thoughts. Sikhism is but one of these thoughts.
Firstly, the British with their policy of divide and rule, and secondly, political turmoil and hatred between Hindus and Sikhs has put the idea of a separate identity in the mind of us Sikhs. Many of my co-coreligionists will say ? but we have different ideas as compared to Hinduism. Sure - I agree that we are different in ways but there are 50 ? 100 major different thoughts within Hinduism and we are BUT one of them.
Do you understand ? Whereas fundamentalist Sikhs we say that we are 1 amongst 7 great world religions the fact is that there are actually 4 great religions. One - Christianity has various branches - Catholic, Protestant, Methodist, Adventist, etc. Second ? Islam has various branches - Shia, Sunni, Ahmediya etc. There is Judaism and finally Hinduism ( which is a collection of various beautiful thoughts like Buddhism, Sanatana Dharma, Sikhism, Jainism, Arya Samajists, Vaishnav, Shaivaites Manbhum, Santhal etc )
So Sikhism is born out of Hinduism. Guru Nanak was born a Hindu, he was a traveling holy man who followed a custom of Sant Mat ( or Saint Tradition ) quite popular amongst saints those days. It was a thought he inculcated in his believers and told them to learn it. His believers were called Sikhs as Sikh means ? ?to learn? We had 9 more Gurus. Yes Guru Nanak also took some minor feedback from Islam but that is the nature of Hinduism ? to absorb from everyone.
Both of these religions are monotheists. Both of these religions do not believe in caste system. Both of these religions do not believe in idol worship. Both of these religions do not believe in fortune telling etc. Both of these religions do not believe in grave worship. Muslims believe in a book called Koran, similarly Sikhs have Guru Granth Sahib.