Introductory text on Group Cohomology What are good introductory textbooks available on Cohomology of Groups?
 A: Also, if you are interested in number theory, http://www.mathi.uni-heidelberg.de/~schmidt/NSW2e/index-de.html (Jürgen Neukirch, Alexander Schmidt, Kay Wingberg:
Cohomology of Number Fields, second edition) and http://www.mathi.uni-heidelberg.de/~schmidt/Neukirch-en/index-de.html (Jürgen Neukirch: Class Field Theory-The Bonn Lectures). [These are textbooks covering (profinite) group cohomology with number theoretic applications in mind.]
A: At the undergraduate level, some elements of group cohomology is explained in John Moody's book "Groups for Undergraduates" http://www.amazon.com/Groups-Undergraduates-John-Atwell-Moody/dp/9810221053  At more advanced (but still undergraduate) level, see Maxim Stykow's Honours B.Sc. thesis "Introduction to
Group Cohomology" http://www.math.ubc.ca/~maxim/stykow_group_cohomology.pdf
At the graduate level, a good choice seems to be the above mentioned Ken Brown's book "Cohomology of Groups" http://www.amazon.com/Cohomology-Groups-Graduate-Texts-Mathematics/dp/0387906886 
