When it comes to Kurdish studies, Martin van Bruinessen is one of the most well-known and respected Western scholars. Although it is now a bit dated, his article “The Kurds and Islam” gives a good overview of the complex relationship between Kurdish identity and Islam. The article mentions a wide number of individuals, movements, and branches of Islam. To the beginner these can be a little overwhelming, but a deep knowledge of these is not entirely necessary for obtaining an appreciation of the various ways Islam and Kurdish identity have influenced one another. If you’re interested in the Kurds, the article is worth your time.
Van Bruinessen’s article can be accessed here.
By the way, basic information about a number of the groups mentioned in the article can be found on Wikipedia and similar sites.