I'm stuck. I'm in Curaw and I need to speak to Lord Naldera but he's not in the castle. Where should I find this Lord and in general the Lord?
The normal way to find a lord is to go to another lord of his faction and choose the
conversation option, and then the name of the lord you are looking for.
This will give you a rough idea of where he is.
Note that there can be glitches here sometimes; once, a lord I was after was taken prisoner, and I only found him MUCH later, after I freed him in battle.