I am working on layingout books, magazines and other printed material for 20+ years. I did a Macedonian edition of "Guinness World Book of 2001", many monographies, biographies, novels, stories, etc. I am an expert for pre-press in InDesign and QuarkXPress and I also use aditional software to have my job done, like Photoshop, Illustrator, CorelDRAW, Xara Designer...
Period of time for finishing the job depends on: how long the book is going to be, how many illustrations/tables/pictures/charts should be placed, if there are more levels of headings, colored text, etc. So, to resume, the book could be done in a day or more.