Summary: There are many great resources out there for learning Clojure. Some of the resources are paid, but fortunately many of the best resources are absolutely free.
Are you interested in learning Clojure? Would you like to get started without risking your money on a book? Is there something that can help you even know whether you want to learn Clojure?
I learned Clojure for free. In fact, I'm a bit of a cheapskate. For many years I would avoid spending money if there was a free alternative. I also keep an eye on resources that pop up around the internet.
I have assembled what I believe to be the best resources to start with if you want to get into Clojure but want to spend $0.
Start here if you have never programmed in Clojure before.
The ClojureBridge curriculum is a community effort that is informed by real-world workshops. It is excellent for starting.
A fun and adventurous guide through the Clojure journey.
A direct approach to bringing more people (especially underrepresented groups) to the Clojure community. The style of this book is very direct and approachable.
For beginners, these two exercise sets will give you plenty of practice with the details of the language.
Exercises you can do right in your browser.
Exercises you do with git and an editor on your local machine.
Editors and Installation
I have built pages for the three main operating systems, thanks to the ClojureBridge curriculum.
An organized list of built-in Clojure functions and macros.
A searchable version of the cheatsheet with documentation, source code, and examples.
Workshops and Events
ClojureBridge hosts free workshops around the world to encourage diversity in the Clojure community. Go to one if you can.
There are many groups on Meetup.com that are interested in Clojure and functional programming. Find one in your area and get in touch.
People chatting in a variety of Clojure-related topics. Very friendly.
Always hundreds of people on and someone to help you if you get stuck.
Clojure discussion group. This contains everything from announcements of new library releases to beginners asking questions.
Ask questions on stackoverflow. They are usually answered very quickly.
A great high-level introduction to the philosophy behind Clojure.
Many of my lessons are free to the public.
Once you've got the basics and need to go deeper.
An open source, community-built book (also available for purchase). It includes many real-world, practical "recipes".
Once you're writing Clojure code, do these exercises and get comments on your style.
These exercises are not Clojure-specific. They are small problems but are usually tricky enough to require deep thinking. I cut my Clojure teeth on Project Euler before other systems existed.
The official documentation.
A searchable community documentation project.
Cross-references between Clojure libraries. Very interesting stuff.
At this point, you may want to think about dedicating some time to learning a different editor. Emacs is the most popular, and many people use vim.
An Emacs plugin called CIDER is the most popular way to use Emacs with Clojure. It gives you lots of functionality.
Many people use vim, so if you like it, here's a setup guide.
If you like Java-style IDEs, Cursive is for you. There's a free, personal license available. Cursive brings a lot of the smarts from IntelliJ IDEA to Clojure, including automatic refactoring, code completion, a debugger, and more.
There is a ton of value in these free resources. But if you'd like to venture into something that is tailored for bringing up up to speed in Clojure from nothing to writing code and you don't mind paying, check out PurelyFunctional.tv Online Mentoring. It's step-by-step guidance from dabbler to Clojure professional.