I scan the booklet (use the best quality settings your scanner can allow), adjust the image to 300dpi (better if your computer won't choke on large images), enlarge them enough and break it up into roughly 8 x 10 sections (there's always some pixelating, but they still look pretty good), then put it together into a pdf for printing (to be sure the size from section to section stays accurate). I even allow there to be some overlap between section images.
It is worth allowing the images to overlap, IMO, and cut them smaller than the image to avoid border lines in the middle of the map. I've tried a couple of methods for mounting but prefer to glue stick them to foam board (available at any art supply or craft store) then cover them with laminate sheets. When I cut them up so they fold, I also add some tape to the back as a sort of hinge.
Some people might keep them all as one large image if they have to computer power to do so and print them on a plotter if they have one, but the best I can do is use the local UPS store which has a $.35 sale on color printing at the moment. I only print b&w at home.
I use maps like those above or
flip mats, DDM maps, maps from the old Dragon (feels weird to call it old),
e-Adventure Tiles, and
map packs, but I place them all on a megamat so that the players never feel they need be confined to the edges of the map.
Hope that helps!