Unfortunately, the audio is incomplete, but Vinay Lal's course at UCLA -History 175c- still gives a compelling series of lectures digging into the biography of Gandhi, his thought and his critics. (feed)
Even if the life of Gandhi and his thought are well-known, there are many surprises when you start digging into it. As a concept, nonviolence is not so difficult to understand, but a theory how this might work in a political theory and in a spiritual philosophy is far from self-explanatory. Vinay Lal's lectures are a good way to get acquainted. Although Lal certainly reveres Gandhi there is ample distance to let you feel you are getting a fair introduction.
In comparison, the old Berkeley courses on nonviolence are much more engaged. These two, PACS 164A&B are among those podcast lectures that are no longer available through Berkeley, not even among the classical courses on iTunesU. The Metta Center for nonviolence however still points at them, including video recordings of those lectures. Should you want to take on these, start with Lal's course.
Lal's course is a great complement to other podcasts about Gandhi. When Joseph Lelyveld published his controversial biography of Gandhi, I reviewed a couple of podcasts that paid attention to this book.
Also among other Indian History courses Lal teaches at UCLA this one stands out. It clearly is the subject that is most closely to Lal's areas of interest. The other courses are History of India and the History of British India.