The Public Radio program Speaking of Faith
aired a program "Understanding Charles Darwin" and prepared a website
that looks most worthwhile. You can hear the program at the website as well.
Included at the site are pages from Darwin's notebooks (including the famous "Tree of Life" pictured here) with an interactive feature that allows the close inspection of each. In addition, there are transcripts of the pages (Darwin often commented on his bad handwriting) and commentary on the meaning of the passages by David Kohn, Oxnam Professor Emeritus of Science and Society at Drew University.
Then there is this statement by James Moore, co-author of the well-known the biography, Darwin: The Life of a Tormented Evolutionist, that some may find surprising:
Darwin's understanding of nature never departed from a theological point of view. Always, I believe, until his dying day, at least half of him believed in God. He said he deserved to be called an agnostic, but he did make the point later in life that "when I wrote The Origin of Species, my faith in God was as strong as that of a bishop.".
It looks to be both interesting and useful.