I am sure most people already use this but I always refer to students to the Organometallic hypertext book. It has excellent explanations of topics such as back-donation in organometallic complexes.
Biological Inorganic Chemistry: Structure & Reactivity edited by Bertini, Gray, Stiefel, and Valentine was published by University Science Books (copyright 2007). It is a detailed text divided into 2 parts. Part A gives "Overviews of Biological Inorganic Chemistry" while Part B goes into more specifics of "Metal Ion Containing Biological Systems." Several prominent bioinorganic chemists have contributed chapters to the book in their various areas of expertise.
I teach my organometallics course, a junior/senior level half-course, entirely as student-led presentations of the primary literature. In the past, the course was populated almost entirely with seniors who had already taken a one-semester advanced inorganic course. This past year, I taught it to juniors and seniors, and the juniors had not taken inorganic yet. A description of the course first appeared in J. Chem. Educ. in 2007 (link below). This VIPEr learning object is an update of the original paper based on my experience over the past two years.