I haven't taken the course, but have mentored it, and of course as bookstore manager, I ship it out to people. I have gone over the course several times, and here are my opinions.
The course is very basic, well written, and covers the main subjects of bonsai.
The success of the course depends on contact with the mentor. It doesn't have to be face to face but that helps.
It depends on your experience. If you have done a lot of bonsai before, you probably have done everything in the course. However, the course tells you why you did some of the things you did.
If you have been in bonsai for less than a couple of years, then the course will help you.
The course should be supplemented with a local bonsai club's beginner course. At most of these beginner courses you get a brief explanation of what is covered in the course and style a tree with the help of a local club member. I highly recommend joining a local club. This is where the information in the course is implemented.
The DVD that comes with the course is excellent. In this DVD you see a lot of the things in the text portion of the course.
So the bottom line is I would recommend the course if you have been in bonsai less than a couple years. If you have been in longer than a couple of years, I would recommend looking at some of the books that the bookstore offers. The wiring booklet covers the basics of wiring. The book ‘Introduction to Bonsai’ covers the material in the correspondence course in another way and has some great pictures.
The Naka books are the “bible” of the hobby. They are excellent reference manuals done by one of the greatest masters. It is not easy reading but is excellent as a reference (thousands and thousands of copies have been sold worldwide). There are also specialty books on specific topics like maples, junipers, pines.
One final book that I can recommend is the “Basic Bonsai Design”. Unfortunately it is out of print and the author is re writing it. It should be ready for distribution in the first quarter of next year.
I hope this helps. You can always reach me at email@example.com
if you have more questions.