GURU GRANTH SAHIB
Sikhism is a non-Semitic, Aryan, non-Vedic religion. It is a religion that has the sixth largest following in the world. There are approximately 23 to 27 million Sikhs in the world today. It was founded by Guru Nanak at the end of the 15th century. Sikh Guru applies only to the ten Gurus who founded the religion starting with Guru Nanak in 1469 and ending with Guru Gobind Singh in 1708; thereafter it refers to the Sikh Holy Scriptures the Guru Granth Sahib. So Guru Granth Sahib is the Sikh Holy Scripture. 
The Guru Granth Sahib contains the scriptures of the Sikhs. It is an anthology of prayers and hymns which contain the actual words and verses as uttered by the Sikh Gurus. Sikhs regard the Guru Granth Sahib as the living Guru. The Guru Granth Sahib, also known as the Adi Granth, consists of 1430 pages and has 5864 verses. Its contents are referred to as bani or gurbani. An individual hymn is a shabad.
The Granth was compiled by the fifth Sikh guru, Guru Arjan Dev. He completed task of collecting, compiling, and scrutinizing the hymns and compositions of Guru Nanak and his predecessors. He decided to include not only the hymns of the Gurus but also that of other saints. At the invitation of the Guru, followers of different sects, both Hindu and Muslim, came to the Guru and recited the hymns of their teachers. Guru Arjan chose only those hymns which echoed sentiments he wanted to inculcate in his own community. After the selections were made, the Guru dictated the hymns to Bhai Gurdas ji, who wrote the Granth Sahib.
Having compiled the Granth, the Guru placed it in the newly- built Harmandir Sahib (Golden Temple) in Amritsar. The first parkash (opening ceremony) was performed in the Golden Temple by Guru Arjan on August 30, 1604. The Guru nominated Bhai Buddha as the custodian of the Granth Sahib. At this time, the Guru bowed before the collection, acknowledging the higher authority of the bani to that personal importance and significance which he possessed as Guru. After this time, he no longer sat at a level above the Granth Sahib, but below it. The Guru also instituted daily public worship at the temple where the Granth was recited all day long to the accompaniment of stringed musical instruments (kirtan).
With the passage of time, the original Granth Sahib passed on from Guru Arjan to Guru Hargobind and then to his grandson, Dhir Mal, who took permanent possession of it. To restore the Granth compiled by Guru Arjan to the Sikhs, Guru Gobind Singh ji sent some Sikhs to Dhir Mal's descendants, who possessed the original Granth Sahib, and requested for its return. But they refused to part with it and asked the Guru to write his own Granth if he was a real Guru. Therefore, the second version of Guru Granth Sahib was prepared by Guru Gobind Singh in 1706. At Damdama Sahib, Guru Gobind Singh dictated the entire Granth Sahib from his memory to Bhai Mani Singh ji; the Granth Sahib was dictated word by word as it originally was. At this time, Guru Gobind Singh re-edited the Adi Granth to the form in which we find it today. The Guru removed some unauthenticated writings in the Granth and added four hymns in the beginning for evening prayers. Guru Gobind Singh also added several hymns from his father, Guru Tegh Bahadur.
Guru Gobind Singh ended the line of living Sikh Gurus by raising the Adi Granth to the status of a permanent Guru. He commanded the Sikhs that it was to be revered as the body and spirit of the ten Gurus.
The Granth Sahib contains 937 hymns of 36 Hindu saints, Muslim sufis and bards. The hymns of the these holy men cover a period of six centuries (from the 12th to the 17th century). Regardless of the author, this gurbani has an equal status as the hymns of the Gurus.
There are also some hymns from Sikhs during the time of the Gurus, including those from Baba Mardana ji, Baba Sunder ji, Sata Doom, and Rai Balwand. In addition, the Granth Sahib includes some bani from eleven bards (bhats) who came to the court of Guru Arjan in 1580. They were men of wisdom and were much impressed by the personality and the work of the Guru. Their names are Kalashar, Jalap, Kirat, Bhikha, Sal, Mathura, Bal, Bhal, Nal, Gayand, and Harbans. Yet, overall, the majority of bani in the Guru Granth Sahib contains the hymns of the Gurus:
The Guru Granth Sahib starts with Guru Nanak's composition, Mool Mantar followed by Japji, Rehras (the morning and evening prayer respectively) and Kirtan Sohila, the night prayer. This introductory gurbani occupies the first thirteen pages of the Guru Granth Sahib.
Jap Ji, also called Guru Mantar, was written by Guru Nanak. It occupies about 9 pages and consists of 40 sloks, called pauries of irregular length. The mode of composition implies the presence of a questionnaire and an answer. Jap Ji is followed by Sodar Rehras, another composition by Guru Nanak, although later on additions were made to it by Guru Ram Das and Guru Arjan Dev. Sodar is the yearning of the soul for the door of the house of God. Kirtan Sohila follows Sodar and occupies a little over one page. It was also composed by Guru Nanak but has additions by Guru Ram Das and Arjan Dev.
The next portion of the Granth is divided into thirty one sections each according to a particular raga. This portion occupies 1154 pages.