I have been playing the didgeridoo for 22 years and have been teaching for the last 3 or 4 years. I taught myself to play using a book and cd from the local library. I found it easy to learn but most people find it difficult. Lessons can set you on the right path and crucial corrections in your technique can make a huge difference and help you avoid wasting hours playing incorrectly as you learn.
Circular breathing is your first fundamental and essential skill.
Practice is, of course, the key factor. Play with your eyes closed and FEEL what your lips and tongue are doing while you play. Pay close attention, repeat about a million times and voila!, now you too can play the didgeridoo :- )
Lessons are in my home, or your home for a small additional fee to cover my transport costs.