Andronik, Catherine M.Copernicus: Founder of Modern Astronomy. Enslow, 2002. A good discussion of the scientist's youth and those who influenced his life. For grades 4 to 8.
Rosen, Edward.Copernicus and His Successors. Hambledon, 1995. Critical review of the life and work of this 16th-century astronomer, written by the foremost Copernicus authority.