*** Mesopotamian Myths *** by Henrietta McCall A 1990 book from the British Museum Publications.
The first half is dedicated about the "context".
The first chapter retells the history of the findings of the clay tablets where those myths were written and the process of understanding the cuneiform scriptures (as paradoxically, it's the oldest civilization but its cultural legacy was only acknowledged "recently")
The second chapter is about the state of the collection of tablets and the place and organization of litterature and "writings" in this civilization.
Third chapter makes up a comprehensive list of the gods and describes the social structure of the Mesopotamian society.
The second half of the book is dedicated in the myths themselves (Gilgamesh, Marduk, Ishtar, etc...). They're presented in an interesting and informative form as due to the damaged original material they're mostly incomplete but the author makes a good job at telling the stories, explaining them, filling the missing details and translating directly some excerpts so you can can get a good grasp of their inherent poetry (close to Homer or the Indian tales).
The book is short, very informative and pleasing to read. The original English edition is out of print but the French one is still available. In replacement, there's the
Dalley book which was originally edited a year earlier but got a revision in 2009, probably with new knowledges and discoveries (I haven't read it yet).