We'll start with the Wikipedia entry on Coaching. This article provides some good definitions and links to a number of articles about specific types of coaching.

Esther Derby is a person I have met a couple of times through the agile community. She has a wonderful approach to training and facilitation. This article about coaching is a simple introduction to the tools of a coach.

This is a brand new blog about lifestyles. There are only two entries so far, but both are interesting. I enjoy the style of writing which is quite personable. The author seems to be positioning the blog as a lifestyle coaching resource.

And the International Coach Federation which seems to be one of the most well-known bodies that promotes coaching as a profession.