Hi there,

You might be interested in some of the following memoirs:

At Hitler's Side: The Memoirs of Hitler's Luftwaffe Adjutant 1937-1945 by Nicolaus von Below

He Was My Chief: The Memoirs of Adolf Hitler by Christa Schroeder

The Hitler I Knew: Memoirs of the Third Reich's Press Chief by Otto Dietrich

Hitler Was My Friend: The Memoirs of Hitler's Photographer by Heinrich Hoffmann

Hitler's Last Secretary: A Firsthand Account of Life with Hitler by Traudl Junge

Hitler's Last Witness: The Memoirs of Hitler's Bodyguard by Rochus Misch

I Was Hitler's Pilot: The Memoirs of Hans Baur by Hans Baur

With Hitler To The End: The Memoir of Hitler's Valet by Heinz Linge

I Shall Bear Witness: The Diaries of Victor Klemperer, 1933–41 by Victor Klemperer

To the Bitter End: The Diaries of Victor Klemperer, 1942–1945 by Victor Klemperer

Inside the Third Reich by Albert Speer

The Secret War Against Hitler by Fabian von Schlabrendorff

Lost Victories by Erich von Manstein

A woman in Berlin by Anonymous (this deals with the end of the war)

Bear in mind that all of these are primary sources, so don't believe everything you read (this is especially aimed at Manstein).