Buy a used work-horse printer. (This is the expensive part. Luckily, it doesn’t have to be repeated very often.) The former life of my printer was in an office somewhere, but it's similar to many printers I've seen in high-school computer labs. I did look into buying a nineteenth-century printing press, but it weighed a ton (literally: it tipped the scales at 2,000 pounds.) My floorboards couldn’t take the weight.
Download free imposition software off the internet. This is the program that puts the text pages in the correct order (each sheet of paper = 4 text pages, in nothing approaching consecutive order.) I use a program called Cheap Imposter.
Convert the file to pdf format so that it will be compatible for the imposition software.
Run the file through the imposition software.
For books with color illustrations: Go to local printshop, and print out illustrations on their high-quality color printer.