I'm sort of a new player, but I've been reading the wikis intensively and searching the boards for answers. I've finally come across a problem I cannot solve on my own.
I'm getting zombie sieges in my first winter. The first time this happened, I fought, then had to abandon the fort. This time, I hard-restarted (and backed up) because I really liked the embark site and the way the first few months had gone.... up until I got 2 necromancers and 26 zombie elves, and I only had 14 dwarves (and 7 children), and a few untrained dogs.
I accidentally erased the anvil at the embark prepare page, so I have to hold out with wood, stone and bone (but I have tons of wood and stone). I have hematite and lignite, though, when it comes. I forget if I had flux, and what the evilness or savageness was, but I think wilderness. There's a bit of river but it's off on the far corner. I have my trade depot just inside the hillside, with a 3x14 hallway to it, and then a 1x10 hallway back to the rest of my fort. There's a couple of rooms coming off the place where the 3x hallway narrows into a 1x hallway (I've been storing a few trade goods and some wood), and a great room just at the end of the choke point, currently a dining hall and dormitory. Directly underneath is a bigger great room that I had meant to turn into a better dining hall, but I haven't put anything there yet, so I could build a pit trap room.
What traps/pits/etc can I or should I build? How do I kill or trap zombies until I can muster a military, or at least some armor?