First off, this game is easy, though it's harder than the first. There's still times where all my teammates flee and I'm left standing against a horde of zombies. That's epic.
Anyway, the first thing to note is that you can pick which places to loot when you're searching. Houses sometimes have people. Anything with a gun icon is likely to have a weapon you'll want.
The thing to keep in mind is that you're not really in a rush. I just went exploring and hit every place on the map and still made it with 3 days to spare. Lay around, gather extra supplies, find extra survivors, and don't worry.
Gathering extra supplies means that if you get in trouble farther down the road, you don't have to go through as many fights in the harder areas because you've already got the supplies to move on.
The best path to take is Claysburg -> Aspenwood -> Jonestown -> Union City. There's no real need to go to Fort Tran, it's mainly just a way to get out of Jonestown in a hurry if you don't have the supplies to visit Union City.
That said, VISIT FORT TRAN ANYWAY. It has the most awesometastical weapons you've ever seen. There's the m249 machine gun which is like the uzi only with 200 rounds. There's also the RPG. That's right, a rocket launcher. It has a slow reload time, but who cares. When a whole group of zombies runs toward you, you can take them out with one or two shots. Then, hit the stragglers with your m249. You probably won't even have to reload the second gun. True, you only need these guns to kill the zombies that you could have avoided in the first place but so what? It's fun. Those who still complain need to look up the definition of the term "game."
Notes on the placement of mines: Bear traps don't do a whole lot. Gas can are awesome if they go off at the right time, but since they usually get hit in the crossfire they're not all that or a bag of chips. Trip mines are the best. No matter what, save all your mines for Jonestown, because that's when you need them. What about Fort Tran? You won't need them because that place is weapons heaven (or zombie hell).
