Oh man, it's been a long time since I've table-topped, but back in the good old days when I did play/GM at the table, we used to use a "battle mat." I don't remember what they were actually called but they came in various scales with both hex and square grids on a light brown cloth/vinyl background. You could get them at pretty much any gaming supply store and could use dry-erase markers on them as long as you didn't let the ink set there too long.

I wouldn't map things out for the players in detail, but when they needed the limits of the encounter space, it came in handy both for drawing and as a means of measuring distances for the miniatures that we used.

As for myself, I drew out fairly detailed maps for my own reference and often typed/printed up a detailed description of potential encounters/inhabitants and other assorted information. These, I usually kept in a notebook of some sort or, at a minimum, filed away.

GW