For compact objects the basic references are the following:

S.L. Shapiro, S.A. Teukolsky, 1983: Black Holes, White Dwarfs and Neutron Stars, J. Wiley (New York)

N.K. Glendenning, 2000: Compact Stars, Springer-Verlag, 2nd Edition

M. Camenzind, 2004: Astrophysics of Compact Objects, Lecture Notes, LSW (Heidelberg)

Gravity's Relentless Pull: An interactive, multimedia website about black holes for Education and Public Outreach

Virtual Trips to Black Holes and Neutron Stars by Robert Nemiroff (Michigan Technological University)

Neutron Stars and Black Holes in X-Ray Binaries, Jan van Paradijs

X-ray Properties of Black-Hole Binaries, Remillard, McClintock