A short article such as this can't hope to provide a complete introduction to a powerful programming language like Clojure, but it can perhaps whet the appetite. No other language, at least no other JVM-based language, is conceptually similar or as consistent in focusing on concurrency. Learning a Lisp-like language or Scheme is worth it just to have your horizons broadened. But with Clojure and its perfect integration with Java, it doesn't have to end there – it is pragmatic and perfectly suited to practical use.
Stefan Tilkov is author of the book "REST und HTTP", author of numerous specialist articles and a frequent speaker at international conferences.
The main starting point for Clojure is the web site for the language. The Clojure community is large, very active and friendly to newcomers. Rapid answers to questions are to be had on both the Google group and the IRC channel, often enough from Rich Hickey himself. The Getting Started page is a good jumping off point for experimenting with a range of IDEs. In terms of books, Stuart Halloway's Programming Clojure is to be recommended. Mark Volkmann's tutorial offers a compact online starting point. Other recommended books are The Clojure Book, The Joy of Clojure and Practical Clojure.