There is nothing more frustrating than losing one of your best nobles to a concealed spy hellbent on causing you pain. Most alliances like to know what is going on in their territory. Some wont care and will be glad to have you there, others might. Also check around before assuming buildings have been vacated by their owners. I'll try to use this section to address questions posed by new players.
Lets face it.
It's the new players that keep things intresting. Lets do all we can to help them out. Answer - depending on what you need, there is more than likely a skill required and in some cases, a particular type of 'troop' unit required. A few notes on the table above. First person that can prove to me you can recruit peasants in a swamp like the rules say you can, gets 100 gold.