I enjoyed learning Clojure by doing the exercises at http://www.4clojure.com/. I documented my progress and learned a lot from solutions of others.
Clojure simply differs too much from the Lisp languages. For example take into account the "atom" keyword and its meaning in Lisp versus Clojure. And also the way lists are used in Clojure, see "cons" for example.
These are not frivolous differences -- atoms and conses are the key building blocks of the Lisp language!