Ask the civvies in town, they'll mark the guild halls on your city map for you.
Unless they don't like you. All the guilds appear on the map as blue. Shops are orange, and taverns are green.
The dungeon locations on the world map appear as red and orange dots. In the beginning of the game you will only see red dots which indicate smaller dungeons, crypts and graveyards to be specific. The proper dungeon location are marked as orange dots, and will only be revealed through quest givers and occasionally on parchment that you can find in loot lists.