Sorry to tell you, but there's really nothing about the 'osiris myth' during the the early New Kingdom. There is typical theological aspects, but nothing mythological...
The Contendings of Horus and Seth comes from the Ramesside period, and the stuff at Edfu is from the Ptolemaic period.
Try to get your hands on Lichtheim's Ancient Egyptian Literature. I've also got a bibliography for creation myths. Quirke would be the easiest to get, I think:
Allen, James P. Genesis in Egypt: The Philosophy of Ancient Egyptian Creation Accounts. Yale Egyptological Studies, 2. New Haven, 1988. An excellent study of Egyptian thought on creation centering on the interpretation of specific texts and stressing the positive theological value of Egyptian creation mythology.
Anthes, Rudolph. Egyptian Theology in the Third Millennium B.C . Journal of Near Eastern Studies 18 (1959), pp.169–212. A very intense study of the Heliopolitan creation tradition and its political implications. This study will provide the reader with a good understanding of Old Kingdom myth.
Clark, R. T. R. Myth and Symbol in Ancient Egypt. London, 1959. A very good introduction to the symbolic nature of myth in ancient Egypt, covering most of the important types of myth.
Frankfort, Henri. Ancient Egyptian Religion: An Interpretation. New York, 1948. A general interpretation of the nature of Egyptian religion. Highly useful for an understanding of the Egyptian religious mind.
Frankfort, Henri. Kingship and the Gods: A Study of Ancient Near Eastern Religion as the Integration of Society and Nature. Chicago, 1948. A comprehensive and complete treatment of kingship in the context of the world of the divine in ancient Near Eastern cultures. This work will help the reader to see Egyptian myth in the wider context of its time.
Frankfort, Henri, et al. Before Philosophy: An Essay on Speculative Thought in the Ancient Near East. Baltimore, 1949. A very good exposition of the inner significance of Near Eastern myth, including material on Egypt and other ancient cultures.
Hart, G. Egyptian Myths. London, 1990.
Hornung, Erik. Conceptions of God in Ancient Egypt: The One and the Many. Translated from German by John Baines. London, 1983. Contains many fine insights into the Egyptian theological mind and serves as a very good basis for understanding Egyptian religious thinking.
Lesko, Leonard. Ancient Egyptian Cosmogonies and Cosmology. In Religion in Ancient Egypt, edited by Byron E. Shafer, pp. pp.88–122. Ithaca, 1991.
Quirke, Stephen. Ancient Egyptian Religion. London, 1992. A very well organized overview of Egyptian religion; useful for setting creation mythology in its wider setting and for seeing Egyptian myth as a living force.
Tobin, V. A., Mytho-Theology in Ancient Egypt . Journal of the American Research Center in Egypt 25 (1988), pp.169–183. This article will provide a concise and easily readable account of the nature of the Egyptian mythic corpus.
Tobin, V. A., Theological Principles of Egyptian Religion. New York, 1989. A systematic theology of ancient Egyptian religion, stressing the place of creation mythology.
