Thomas Schreiner's 40 Questions About Christians and Biblical Law is an excellent resource. See my review here. Concerning Luke's view of the Law in both his Gospel and Acts, Schreiner summarizes,
"Luke must be read discerningly in order to grasp his view of the law. On first glance he way seem to be an unabashed supporter of the law; but when he is read more carefully and in light of the story of both Luke and Acts, it becomes clearer that the law should be interpreted in light of salvation history. Now that the new covenant has arrived in Jesus Christ the law no longer occupies center stage. The law must be interpreted in light of Jesus Christ and his coming. It was the will of God to keep the law during the old era of salvation history, but the law is not required for the salvation of the Gentiles. It is no longer normative now that Christ has come" (p. 179).
Schreiner, Thomas R. 40 Questions About Christians and Biblical Law. 40 Questions Series, ed. Benjamin L. Merkle. Grand Rapids: Kregel, 2010.