Hi there!
Sorry for the late reply, but the mini map is available via the ']' keyboard shortcut (or as a toggle in the user interface settings section). Repair vendors and the like will appear on the mini map with an appropriate icon for the general content of their sellable inventory.
On the story mode server/game 'Shadow of Moritasgus', the town is directly north of the initial farm spawn area. On procedurally generated worlds, there are no vendors yet, but that is something I am actively working on fixing for the next release (0.8.2).
I hope this answers your question!
Cheers,
Chris