General Motors began essentially as a local Flint business.The following books are good places to start researching GM.
For more primary sources on Flint automotive history try the following archives.
In 1905 William Crapo Durant managed to convince enough local Flint investors to pledge enough money to bring the Buick Motor Company back to Flint from Jackson, Michigan. Many of these investors were his relatives, children and grandchildren of Henry Howland Crapo, who came to Flint in 1857 to develop a tract of timber, then became governor. A microfilm copy of H. H. Crapo's business papers, as well as other items relating to the Crapo family, is in the GHCC.
Durant's life is covered in the following two biographies.
Billy Durant: Creator of General Motors by For more primary sources on Flint automotive history and the personal papers of many early automotive pioneers, including some of Billy Durant, try the Kettering University Archives.
Charles Stewart Mott (1875-1973) brought his Weston-Mott Company to Flint in 1907, becoming GM's largest stockholder, and dominated Flint's political, social, and cultural life through most of the 20th century.
No biography of him has been attempted, and his personal and complete business papers are not available for research. However, the following resources give glimpses into Mr. Mott's life.
University of Michigan-Flint