Some books:
I would not waste your time with S.G.M. Weerasighe's "A Comparative Study of Early Buddhism and Kantian Philosophy." Even though it sounds fantastic, it's not. I have it. I might pull an idea or two for my thesis (which is practically based on the exact same topic), but probably not.
I WOULD have a look at Philip Olson's "The Discipline of Freedom: A Kantian View of the Role of Moral Precepts in Zen Practice." It is a very good, scholarly (even though the author is a lawyer and zen priest) approach to the topic - though written lucidly so that a lay reader will have no trouble.
Websites of present interest:
GUYER, PAUL (1998, 2004). Kant, Immanuel. In E. Craig (Ed.), Routledge Encyclopedia of Philosophy. London: Routledge. Retrieved June 11, 2009, from http://www.rep.routledge.com/article/DB047
Kant: An Overview
LibriVox - Kant's books read to you!
Lawrence Hinman's Ethics Site.