Read in his own words:

“… I was a simple man, but I trusted my Guru. What he told me to do, I did. He told me to concentrate on “I am” — I did. He told me I’m beyond all perceivable and conceivable – I believed. I gave him my heart and soul, my entire attention and the whole of my spare time. As a result of faith and earnest application, I realized my self (swaroopa). You may choose any way that suits you; your earnestness will determine the rate of progress” -Nisargadatta Maharaj

If you love books, love his extraordinary book “I am that.”