Mr123
A book or sefer is a great start but it will only help you so much. Emunah requires thought and reflection. Think about all the good things you have in your life and try to be aware of the daily chassadim Hashem does for you. Try to see the Hashgacha Pratis in your life.
The way to really connect with Hashem and build real emunah though is through Tefillah. Work on your Davening and talk to Hashem like its just the 2 of you.
I would certainly recommend Rav Millers books. Many of my Rabbeim have recommended his book and although I never read through any of his books from cover to cover, I have read bits and pieces over the years. Additionally, I have heard or read many things brought down from him and they really open your eyes to proper Torah Hashkafah.