We give an introduction into the ideal structure and representation theory of
crossed products by actions of locally compact groups on C*-algebras. In
particular, we discuss the Mackey-Rieffel-Green theory of induced
representations of crossed products and groups. Although we do not give
complete proofs of all results, we try at least to explain the main ideas. For
a more detailed exposition of many of the results presented here we refer to
the beautiful recent book by Dana Williams.