Reddit mentions of Sufism and Taoism: A Comparative Study of Key Philosophical Concepts

A couple of books on the more scholarly side; Sufism and Taoism and Mystical Dimensions of Islam are good, if somewhat deep and dense, and useful, orienting. The works of Henry Corbin, such as Spiritual Body and Celestial Earth and Alone With the Alone: Creative Imagination in the Sufism of Ibn Arabi, are illuminating. Look into the Sufi mystics themselves as much as commentary, there should be a list somewhere online but Ibn Arabi, Suhrawardi, Jabir Ibn Hayan ('Geber'),Avicenna and Hallaj as well as the more well known Rumi come to mind. Your best bet if you really want to learn about Sufism is to take up instruction under a Shaykh in an order. Depending on where you are there is possibly a local order you could attend meditations and classes with?

https://www.amazon.com/Sufism-Taoism-Comparative-Philosophical-Concepts/dp/0520052641

http://www.ucpress.edu/book.php?isbn=9780520052642

https://www.scribd.com/document/263605121/sufism-and-taoism-a-comparat

http://www.seekeraftertruth.com/toshihiko-izutsu-sufism-taoism/

Try this:
http://www.islambuddhism.com/docs/CommonGround.pdf esp p.79

Also regarding Islam and Taoism

https://www.amazon.com/Sufism-Taoism-Comparative-Philosophical-Concepts/dp/0520052641

The Tao Te Ching is also a religious text. And the Quran is also a deeply philosophical text.

If you're interested in learning how they are related, you should read Sufism and Taoism: A Comparative Study of Key Philosophical Concepts. It is by Toshihiko Izutsu, a renowned Japanese scholar of theology.