D. A. Porter and K. E. Easterling, Phase Transformations in Metals and Alloys, Chapman and Hall, 1992.
Chapter 4 covers solidification. Earlier chapters cover phase diagrams, diffusion, and microstructure. Later chapters cover solid-state transformations.
Matter module: Solidification
This website covers much of the same material as this TLP, but also has more content covering the kinetics of solidification, and the formation of a eutectic structure.
This page covers dendritic solidification, and contains many images of dendrites. The page links to a selection of movies showing dendritic solidification.