Even before the establishment of the Delhi sultanate in India. Sufis had been in India. Many of them were fleeing from the advancing armies of the Mongols. In India there were two important sects of the Sufis the Suharwardy sect and the chisti sect.
Moinuddin Chisti (AD 1141-1238) was one of the most revered of the Suri pirs. He came from Lahore and made Ajmer his home. All his life he worked for the poor. He felt that service of god meant service of humanity. Even today his dargah at Ajmer is a popular holy place. Nizamuddin Auliya was famous Sufi pir of the 14th century AD. He set up his Khanqah (Order or monastery) in Delhi. He asked his followers to lead simple austere lives and spend their time seeking god. Amir Khusrau was one of the best known Sufi poets. He was a disciple of Nizamuddin Auliya.
Here you can buy a large collection of books on Sufism.