Superman stories, not complete anthologies
Superman: The Golden Age Omnibus Vol. 1 is DC’s official hardcover that places the 1938 Superman debut in the context of the first years. DC does not reprint complete Action Comics issues here (Zatara, Tex Thomson and the other features are omitted), but the cover reprint and Superman story from each issue.
The book collects Superman tales from Action Comics Nos. 1–31 (1938–1941), the first solo issues Superman Nos. 1–7 (from Summer 1939) and New York World’s Fair Comics Nos. 1–2 (1939/1940). Foreword and afterword are by Jim Steranko; the series cover is by Darwyn Cooke.
Action Comics No. 1 in the omnibus
From the debut issue (on sale April 18, 1938, cover-dated June) the volume takes the iconic cover (Superman lifting the car), the short origin page and the roughly thirteen-page story “Superman, Champion of the Oppressed!”. If you want the complete 64-page newsstand pamphlet as an object, choose a facsimile or the single-issue reprint.
Key issues in this volume
Beside No. 1 are the stories that complete the mythos: Superman No. 1 (the Kents, the name Krypton), Action Comics No. 13 (the Ultra-Humanite) and No. 23 with the debut of Lex Luthor. For the historical frame of the first issue, see the history of the first issue.