If you're dealing with maps in a book, my most important advice is to get the equivalent PDF. For a PDF, there's a free utilty for Windows (don't know if it's available for Mac or Linux) called PDF Creator, which despite it's name also allows you to print out pages of a PDF as a JPG or PNG graphics file. I've used it to convert a PDF map to graphic and then enlarged it with Paintbrush Pro - used a few other apps for enlarging too. If I'm not happy with the quality of the map, I might bite the bullet and import it as a background in Campaign Cartographer and then just trace and build over it.
Otherwise, when I was running adventures IRL around a table, I use a sizable assortment of Paizo's 5"x8" tiles. I found if the genre aligns (i.e. Fantasy subgenres), I can quickly build an equivalent map with them. I actually like the format of those tiles so much, that I've started to create my own tiles with Campaign Cartographer for other genres.
I had experience creating maps by hand back in the day, so I'm comfortable with hand drawing out a map on a grid real-time as an exploration unfolds. Definitely some advantatges with that, as IMO it's the best way to ensure fog of war is in effect for encounters. If it's an old school, square-edged dungeon like the old blue no-copy maps, I provide grid paper and encourage one of the players to take on the duty as mapper. The session takes longer to run when doing that, but IME it really enhances the OSR vibe.