Info and images from Andriasang.com
You have a mini map in the corner of the screen, but you can also bring up a larger map, or you can use the signposts along the way.
You can call out to others in battle, which will raise their tension. Also those that have their name listed in orange are low on HP.
Treasure chests are scattered around the world as are the "shiny spots" like DQ 9 had.
This and other images are on the Screenshots page.