Mason’s first book was: A Computer In The Art Room: The Origins of British Computer Arts 1950-1980, and she was also one of the editors of: White Heat Cold Logic: British Computer Art 1960-1980.
1. Do your research. Locate the main players in your field who already publish similar books, and approach them first. Find out their preferred proposal formats (the publisher’s website will tell you this information often in great detail – follow it).