Hover over a building on the map and a card tells you what it's good for — boards and tools at the hardware store, guns at the police station, medicine at the pharmacy — along with how long a trip takes, what you'll probably bring back, which weapons might turn up and how likely they are, and whether somebody may still be hiding in there.
Right-click it (or just click) to send someone. The menu shows each survivor's time, risk and how good a scavenger they are, so the choice of who goes is made right where you're looking.
Guns are now a lucky find early on and become more likely as the days go by. Tools like a crowbar turn up from the start.
ZEKE!