What? This is my simple and easy way to determine how the Ironbreakers (and any other party like it that has a home staffed with servants) hear rumors. Of course, there's always the normal rumor mill: going to a tavern and chatting with locals hardly ever fails. However, since the Ironbreakers have a staff now and a house, it is likely that they can get rumors from many places at once. Indeed, even the smallest household begins to resemble a ring of spies.
Determine City Sections and/or Jobs
In a huge city like Miles, servants are likely to go and visit the same sections over and over; there will be one in charge of purchasing all the wine, for example, and another in charge of going to the fishmarket each morning to see what the catch is.
The next step is to determine what kind of things gets talked about in each area and how likely it is that a servant will hear a juicy new bit of gossip there.
Flesh out News Type
Grainmarket -- 1 in 4 chance/week
The grainmarket receives shipments from Khewed and Colona, making it a hotbed of news from overseas. This includes updates from Ninfa, the East, Chimeron and High Aellon, as well as places in the south like Ralashar. It is the city's primary international marketplace.
Then I list 10 rumors current for the month, and viola! Any servants attending the grainmarket have a chance to hear one of them.
EDIT: This is, of course to be complimented with the Greyhawk Grognard's lovely Rumor Epidemiology chart.