The most-referenced Clojure tutorial seems to be the one that Mark Volkmann (a software development guru here in St. Louis) put together. It is entitled Clojure - Functional Programming for the JVM, and steps through Clojure starting with the basics. It is rather long and quite detailed - expect to spend considerable time working through it.
There are two WikiBooks about Clojure:
Learning Clojure is a similar effort; it is not entirely clear to me what the difference is, from a few minutes of comparison.
Koans and Exercises
Once you’ve absorbed the basics, working through the Clojure Koans is a great way to test and extend your understanding. (In this context, “koan” means approximately “brain puzzler meant to build understanding”.)
Several other sets of exercises are linked on this Stack Overflow page