Here are some full text books about Gold and Gold mining.

• California Gold (1933 magazine reprint), by James Stephens Brown (HTML at LOC)

Stephen's diary includes his narrative concerned with the gold rush, the major part of his journal.

• California Gold Rush Merchant, by Stephen Chapin Davis (HTML at LOC)
• California: Its Gold and Its Inhabitants, by Henry Veel Huntley (HTML at LOC)
• California Sketches, With Recollections of the Gold Mines, by Leonard Kip (HTML at LOC)
• Capt. J. D. Winchester's Experience on a Voyage from Lynn, Massachusetts, to San Francisco, Cal., and to the Alaskan Gold Fields, by James D. Winchester (HTML and page images at LOC)
• Digging for Gold: or, Adventures in California, by R. M. Ballantyne (HTML at Athelstane)
• The Exploring Expedition to the Rocky Mountains, Oregon and California, by Brevet Col. J.C. Fremont, To Which is Added a Description of the Physical Geography of California, With Recent Notices of the Gold Region From the Latest and Most Authentic Sources (fifteenth thousand, 1852), by John Charles Frémont (Gutenberg text)
• A Fleece of Gold: Five Lessons from the Tale of Jason and Golden Fleece (second edition, 1905), by Charles Stewart Given
  • PDF at Case Western
  • Gutenberg text
• A Frenchman in the Gold Rush, by Ernest de Massey, trans. by Marguerite Eyer Wilbur (HTML at LOC)
• Getting Gold: A Practical Treatise for Prospectors, Miners, and Students (second edition, 1898), by Joseph Colin Francis Johnson (Gutenberg text)

Gold and debt: an American hand-book of finance, with over eighty tables and diagrams illustrative of the following subjects: the dollar and other units; paper money in the United States and Europe; gold and silver in the United States and Europe; suspensions of specie payments; the era of gold; values of the precious metals; the era of debt; the rise and fall of prices; also, a digest of the monetary laws of the United States./ By W. L. Fawcett.
Fawcett, William Lyman
Chicago: S. C. Griggs and company1877.

• Gold and Debt; An American Hand-Book of Finance, by William Lyman Fawcett (page images at MOA)
• The Gold Seekers of '49, by Kimball Webster (HTML at LOC)
• Handbook to the New Gold Fields: A Full Account of the Richness and Extent of the Fraser and Thompson River Gold Mines (1858), by R. M. Ballantyne (page images at canadiana.org)
• Hard Drive to the Klondike: Promoting Seattle During the Gold Rush (1998), by Lisa Mighetto and Marcia Babcock Montgomery (illustrated HTML at National Park Service)
• The Inside Story of the Gold Rush, by Jacques Antoine Moerenhout (HTML at LOC)
• Kaffir, Kangaroo, Klondike: Tales of the Gold Fields (Toronto: R.H.C. Browne, c1898), by Thaddeus William Henry Leavitt (page images at canadiana.org)
• Klondyke nuggets: Being a Brief Description of the Famous Gold Regions of the Great Canadian Northwest and Alaska (New York: American technical book co., 1897), by Joseph Ladue (page images at LOC)
• A Lady's Visit to the Gold Diggings of Australia in 1852-53, Written on the Spot, by Ellen Clacy
  • PDF at SETIS
  • Gutenberg text
• Legacy of the Gold Rush: An Administrative History of the Klondike Gold Rush National Historical Park, by Frank B. Norris (illustrated HTML at National Park Service)
• A Letter from A Gold Miner, Placerville, California, October 1850 (with an introduction by Robert Glass Cleland), by S. Shufelt (HTML at LOC)
• McNeil's Travels in 1849, To, Through, and From the Gold Regions, in California, by Samuel McNeil (HTML at LOC)
• Memories of Early Wisconsin and the Gold Mines, by John Barber Parkinson (HTML and page images at LOC)
• Midas Gold, by Butterick Publishing Company (HTML and page images at LOC)
• One Man's Gold: The Letters and Journal of a Forty-Niner, by Enos Christman (HTML at LOC) 
• Overland to Cariboo : an Eventful Journey of Canadian Pioneers to the Gold-fields of British Columbia in 1862 (Montreal; Toronto: W. Briggs; S.W. Coates, 1896), by Margaret McNaughton (page images at canadiana.org)
• The Radiochemistry of Gold, by J. F. Emery and G. W. Leddicote (PDF at lanl.gov)
• Sights in the Gold Region, and Scenes by the Way, by Theodore Taylor Johnson (HTML at LOC)
• Six Months in the Gold Mines, by Edward Gould Buffum (HTML at LOC)
• Sixteen Months at the Gold Diggings, by Daniel B. Woods (HTML at LOC)
• A Trip to the Gold Mines of California in 1848, by John Alfred Swan, ed. by John A. Hussey (HTML at LOC)
• Twice Bought: A Tale of the Oregon Gold Fields, by R. M. Ballantyne (HTML at Athelstane)
• Two Women in the Klondike: The Story of a Journey to the Gold-Fields of Alaska (New York: G.P. Putnam's Sons, 1899), by Mary Evelyn Hitchcock (page images at canadiana.org)
• A Yankee Trader in the Gold Rush, by Franklin Agustus Buck (HTML at LOC)