China Web 2.0 Review has an article on Podlook, which purports to be the largest Chinese podcast directory. Clicking through, looking for something that would be related to learning Chinese, I came across the 学习和教育 directory (it had the characters for 'study' in it) and eventually landed on Hess Educational Organization, which has a Chinese Survival Guide podcast series (iTunes link). Not terribly interesting for me, since I think I know enough Mandarin to survive.
Looking through iTunes podcast directory, I came across My Experiences Learning Chinese (also available at Odeo), a series in English by Joe, who married a Chinese woman with whom he's having a child. Joe, the podcaster, has this as his series' description: "This podcast is a personal diary about my experiences learning Mandarin Chinese, which I am starting 72 hours from now and plan to continue until at least the Beijing Olympics." In one of the first podcasts, he says he learned some Chinese 5 years ago, and knows some phrases from his wife, but wanted some more formal and structured training. Not much Chinese in it, but it's a good insight into what challenges English speakers have and what tools they use when learning Mandarin.