The best introduction to James Fitzjames is William Battersby‘s James Fitzjames: The Mystery Man of the Franklin Expedition (2010).
This is also currently the only Fitzjames biography.

You can read transcriptions of Fitzjames’ Franklin Expedition letters (and letters by other crewmembers) in May We Be Spared to Meet on Earth: Letters of the Lost Franklin Arctic Expedition (2022) Edited by Russell A. Potter, Regina Koellner, Peter Carney and Mary Williamson.

EUPHRATES EXPEDITION AND PERSONNEL

Ainsworth, William Francis Personal narrative of the Euphrates Expedition , 2 Volumes 1888 Online Volume 1 Online Volume 2

Charlewood, Edward Philips Passages from the life of a naval officer 1869 Online

Chesney, Francis Rawdon The expedition for the survey of the rivers Euphrates and Tigris, carried on by order of the British Government in the years 1835, 1836, and 1837; preceded by geographical and historical notices of the regions situated between the rivers Nile and Indus / In four volumes 1850 Online

Chesney, Francis Rawdon Narrative of the Euphrates Expedition: Carried on by Order of the British Government During the Years 1835, 1836, and 1837 1868
Online

Chesney, Louisa ; Chesney O’Donnell, Jane Editor Lane-Pool, Stanley The life of the late General F.R. Chesney, Colonel Commandant, Royal Artillery 1885
Online

Guest, John S. The Euphrates Expedition 1992

Naumann, Ursula Euphrat Queen, Eine Expedition ins Paradies 2006 [This book is only available in German]

Nostitz, Mathilde Pauline Travels of a Doctor and Madame Helfer in Syria, Mesopotamia, Burmah and other lands … Rendered into English by Mrs. G. Sturge. [With a preface by F. von Hochstetter.] 2 Volumes, 1878 Volume I Online Volume 2 Online

Richardson, Henry The Loss of the Tigris: A Poem in Two Cantos, with Notes, Inscribed to the Commander, Officers and Men of the Euphrates Expedition 1840 Online

Ryan, George ‘The Life of Major-General Estcourt’ Lives of our Heroes of the Crimea, 1856 Online

This list of books is just a selection

FRANKLIN EXPEDITION PERSONNEL

Bell, Benjamin Lieutenant John Irving of the H.M.S. Terror, In Sir John Franklin’s Last Expedition to the Arctic Regions: A Memorial Sketch with Letters 1881 Online

Smith, Michael Icebound In The Arctic: The Mystery of Captain Francis Crozier and the Franklin Expedition 2021

Traill, H.D The life of Sir John Franklin 1896 Online

Franklin Expedition

Beattie, Owen; Geiger, John Frozen in Time: The Fate of the Franklin Expedition 2004 

Cyriax, R.J.  Sir John Franklin’s Last Arctic Expedition. The Franklin Expedition. A Chapter in the History of the Royal Navy 1939

Hutchinson, Gillian Sir John Franklin‘s Erebus and Terror Expedition: Lost and Found 2017

M’Clintock, Francis Leopold The Voyage of the ‘Fox’ in the Arctic Seas: A Narrative of the Discovery of the Fate of Sir John Franklin and His Companions 1859
online

Potter, Russell Finding Franklin: The Untold Story of a 165-Year Search 2016

Walpole, Gareth; Potter, Russell Relics of the Franklin Expedition: Discovering Artifacts from the Doomed Arctic Voyage of 1845, 2017

Woodman, David C.  Unravelling the Franklin Mystery: Inuit Testimony 1991

Franklin Expedition historical fiction

Gehrmann, Kristina Icebound: Franklin’s Lost Expedition 2018

Simmons, Dan The Terror 2007

Wilson, John Graves of Ice: The Lost Franklin Expedition 2014

Wilson, John North with Franklin: The Lost Journals of James Fitzjames 1999

The Royal Navy

O’Byrne, William R. A Naval Biographical Dictionary, 3 Volumes 1849 read Vol. 1 online

Cavell, S.A. Midshipmen and Quarterdeck Boys in the British Navy, 1771-1831, 2012

Dickinson, H.W. Educating the Royal Navy: 18th and 19th Century Education for Officers, 2007

Harland, John Seamanship in the Age of Sail : An Account of Shiphandling of the Sailing Man-O-War, 1600-1860 2020

Lever, Darcy The Young Sea Officer’s Sheet Anchor: or, A Key to The Leading of Rigging, and to Practical Seamanship 1808

Miller, Amy Dressed to Kill: British Naval Uniform, Masculinity and Contemporary Fashions, 1748-1857 2021

Smyth, Admiral W.H. Chapman The Sailor’s Lexicon: The Classic Source for More Than 15,000 Nautical Terms 1867 Online