Browne, Janet.Charles Darwin: The Power of Place. Knopf, 2002. The second volume of a detailed, well-received account of Darwin's life by the editor of his papers. The first volume, Voyaging, appeared in 1995.
Stefoff, Rebecca.Charles Darwin and the Evolution Revolution. Oxford University Press, 1996, 1998. A lively account of the scientist's life and career; for middle school to high school readers.