I read this today on another blog (http://tangledtranquility.com/) and it reminded me of the quote I heard my Mother say so many times: "It's not the climb of the mountain, it's the grain of sand in your shoe".
Some times it is the little things that are so difficult for us.
One day I hope to be able to afford to take the CZT training.
There are several books available about zentangles as well. I just ordered "Zentangle 6" by Suzanne McNeill, CZT from Amazon. But if you are just beginning I recommend "Zentangle Basics" and Zentangle 3" as those are my favorites.
If you are a quilter, "Zen-sational Stitches for Quilting" by Suzanne McNeill is a wonderful book as well.