Veer ji here is a list that dass would recommend as these books which have helped me to gain more understanding of Gurmat as they are in English so i will make a list as they are very good reading material.
Divine Mystic Reflections on Gurmat Book 1 & 2 & The Miracle of Ardaas these books are amazing and they changed my life a lot.
Se Kinehiya By Baba Sewa Singh. This book is amazing journey of Baba Harnam Singh Ji a very good book full of pratical experinces.
In search of the true guru. by Bhai Rama Singh Ji i have read bits of online as i don't have a copy. This is a eye opener of one's journey to Sikhi from Hinduism searching for answers.
Bhai Sahib Raghbir Singh Bir Ji is another good choice as i want to buy their books.
Andhitee Duniya by Bhai Randhir Singh Ji (although i have not read all of it it has very distrubing truths of death and the soul ghosts etc according to gurmat and personal experinces)
Anhad Shabad Dasam duaar by Bhai Randhir Singh ji a detalied glimpse of the stages of simran. Although i have read bits not full.
Jail Chittiaan and Autobiogrphy of Bhai Sahib Randhir Singh. I don't have this book but i read online bits of it it is really good. I have heard how peoples life got changed by reading this book is amazing of how Bhai Randhir SIngh Ji was a Gursikh and his journey from college to jail is a masterpiece.
I hope this list helps anyone who is reading this post or topic.
