You have to supply the cover & a print ready PDF (embedded fonts, layout, different inside and outside margins for odd / even pages) and a printed proof is around $14.
For a bulk order of UK books; it’s supposed to be cheaper to avoid US shipping costs and do a separate deal with people like: http://www.lightningsource.com/ as well as an Amazon Create space above. Officially you’re supposed to be a publisher, but there seems to be flexibility in this. I think it’s a £50 set up fee
I can’t pretend to be an expert, but am going through the process above with my better half currently (a non-gardening related book; crime fiction – stay posted! So far the proofs are back from both Lightening Source and Create space and they look excellent – a few more tweaks and another round of proof reading to go. Layout a little trickier; in Word initially and then involved roping in a friend who had Adobe Distiller to create the PDF. We hired a designer friend to draw an illustration for the cover and provide a publishers logo (£300)
Blog experiences of others way also prove useful if you go down this route:http://catherineryanhoward.com/selfprinting/timeline/