You could start with the free program here:
http://drmcdougall.com/free.html
This link will take you the first page of a series that presents the complete McDougall program in summary form. If you can afford books and DVDs, they add inspiration and more details, but everything you need to know to follow the McDougall program successfully is presented in the sequence linked above.
From there, you could move on to Dr. McDougall's archive of newsletters:
http://drmcdougall.com/newsletter/archive.html
There are informative and inspirational articles and recipes for each month of the year beginning with 2002.
Another great source of free inspiration is the collection of Star McDougallers:
http://drmcdougall.com/star.html
Some have written their stories, others have recorded short videos in which they describe their experience of learning to use the McDougall program to heal themselves and recover wellness. They have overcome a wide variety of diseases and conditions using the program: diabetes, rheumatoid arthritis, cardiovascular disease, obesity, migraines, osteoporosis, multiple sclerosis, and others.
Next, there are the low-cost options -- books and DVDs. Here's a link to Dr. McD's online store:
http://drmcdougall.com/books_tapes.html
Many of his books are also available through Amazon.com.
Finally, attending a program in Santa Rosa, California, is the most expensive (and probably most motivating and effective) option. The various programs are described here:
http://drmcdougall.com/health.html
I hope this helps. Let us know if you have further questions.