Here's a set of house rules I wrote for my campaign for finding information about adventure sites during down time.
Roll once when carousing for the first time in a settlement and once every month after that.
New adventure sites can be discovered by thieves as Treasure Hunting (Find Traps), Bards as Loremastery and Mages (and everyone else) as Research. If the character has no applicable skills, the chance is as 0-level Research/Find Traps (18+). The sites found out are in the same tier as the characters.
Every adventure site has rumours associated with it. Apprentice tier (0-level) have 4, Starting tier (1-3) have 6, Adventurer tier (4-6) have 8, Conqueror tier (7-10) have 12, and King tier (11-14) have 20.
Rumours about the adventure site can be discovered by everyone as Carousing (Hear Noise, default 18+). Rolling the same rumour twice will confirm whether it's true or false.
Loremastery, Research-2 or suitable Knowledge-4 can also be used to confirm rumours. Adventurer tier adventure sites are at -3, Conqueror tier at -6 , and King tier at -10.
Finding and confirming rumours takes one month per attempt. (Hirelings are a great help at all of this.)
Characters can hire ruffians to gather rumours. Carousers have a 1/6 chance of finding an adventure site or hearing rumours. They have 5% chance of confirming it. Footpads or reciters have the same chance of finding a site. Footpads have a greater chance to hear rumours. Reciters have a better chance to verify rumours. Sages have the best chances to confirm rumours about a site that fits their specialty, but are really expensive.
Buying information and rumours about sites is expensive. Location of a site costs 40 gp. Any rumours about it also cost 40 gp each. Confirming the rumours is even more expensive (carousers can only confirm Apprentice & Starting tier rumours, reciters can confirm Adventurer tier and sages the highest ones).
Value of the information (in gp).
|Tier||All Rumours||Confirming One||Confirming All|
The values could also be used to evaluate how much information on an interesting target was gathered by members of a syndicate with their Carousing, Spying and Treasure Hunting hijinks. Instead of getting that amount in gp the PC leader of the syndicate would get that much information to help plan a heist/quest to the target site.