Well I just dealt with my first ambush, and boy was it a nightmare.
My defensive wall wasn't set up yet, so the goblins could bypass all my traps. Though this turned out to be the least of my problems. My Dwarves outside apparently didn't decide to head back inside until a minute after I gave the order. By the time my miners and engravers were heading back, the goblins were upon them. Along with my favorite miner (a dwarf who seems to die first in almost all of my fortresses so far), we cut down. Both of my Engravers and a hauler died as well. Eventually the goblins got tired of harassing my workers and tried to siege my base. My military cut them down with two casualties, which is pretty good since it was 9 vs. 18. Only a lone pike goblin managed to escape.
So despite the massive amounts of death that occurred, none of my Dwarves seem phased by it. Most of them are still in very good moods. In fact the only Dwarf who is really upset about it is one of my surviving miners, who has lead a tragic life so far. I have no idea how she lived through the ambush. Last time I saw her about 8 goblins were chasing her down. It may have been because evidently used her baby as a shield, as somehow he died while she escaped. Not only that, but both her arms had been broken during an earlier cave in. In addition to having to shield herself with her own babies mutilated corpse, her husband was also among the only two casualties in the military.
So yeah, I'm not quite sure if she will recover from this. Hope she does, since she's my best miner now.