My play style probably differs from that of vjmdhzgr (everyone has their one), but my standard start is:
All embark points are spent on goods, in particular animals. Thus, all dorfs are untrained. They learn fast enough anyway.
2 miners. Initially only one mines, as I start with a single tile corridor. When it's time to build rooms I engage the second one, and from then on miners rarely are given any other tasks.
I disable all hauling, building, and destruction from fully dedicated dwarves (which differs over time), but start with miner and wood cutter.
1 Carpenter. Frequently also given the woodcutter task, and usually architect as well.
1 Mason. Also architect.
1 Mechanic. Also architect.
1 Farmer.
1 Stone/Wood/Bone crafter (the last skill is usually not used). Frequently architect as well.
Someone who isn't miner or woodcutter gets the task of "militia", i.e. appointed to a one dwarf squad and equipped with the spare axe. If wildlife needs to be whacked, this dorf will have to be sent out (rhesus monkeys need to be taken care of, since they cause a lot of trouble).
At the start I set everyone except the miner and woodcutter on herb gathering to a food stockpile in front of the entrance to be. I tend to cut out the outlines of the courtyard and trade depot in the stockpile to reduce the risk of stuff getting in the way of the building. This is basically overlaid with a pasture/meeting area to get the animals in a reasonable place.
As soon as there are some logs, I shift some dorfs to build the courtyard, something like 10 * 10, with a 3 tile opening. The first year I put my trade depot here (built during the third month of summer), and move it in time for the next caravan (usually only the dorfs and gobbos are left on my maps, so I only get dorf caravans, usually). The area is decked over and i often build a guard dog box on top, with a grate to get the dog supervise all comings and goings.
When the miner hits some rock I build my first drawbridge to plug the entrance into the ground (unless I went straight down, in which case it will appear when I go horizontal). The second drawbridge is put at the end of the entrance corridor, and the third one plugs the courtyard (eventually).
I start with digging out a farm area (and let the farmer actually perform his craft) and follow that up with a workshop area. Then workshops can be built, in particular a central quantum stockpile.
If the fauna appears to be of the thieving kind I try to set up a temporary stockpile in the entrance corridor to try to save some things. This stockpile can later be changed to take from links only and link to the QS, to slowly drain it. Initially I feed the workshop QS only "important" stuff, i.e. excluding food (which never goes there), as well as wood and stone.
A few early cage traps are produced and placed in the entrance corridor to catch local intrusive wildlife (kea's are especially annoying).
Since I bring a fair number of birds on embark, the next section is kitchen, butcher, tanner, and indoor pen, and the birds are then allocated to that pen instead, and I also move the meeting area designation here from the top one, which helps the critters to move by themselves.
Next comes an initial food stockpile (specialized piles should already be designated in the farming area for underground seeds, brewables, and threshables). As food stockpiles are set up, the corresponding items are removed from the temporary outdoor one, and the outdoor pile is changed to take from links only and give to the other piles to slowly be drained.
Time to add a dining hall, which I want to start out as about 11*11, to be expanded to 4 times that (it will double as the command center, so here is where the levers go). A table is put in the corner (which will become the center of the full room), and dining/meeting hall is constructed. The meeting area function is then removed from the fowl pen. The drawbridges are actually useless until I've built the levers here and connected them, but I've never been attacked this early. The emergency measure would be to just plug the entrance tunnel with a wall.
Now it's time to give the dorfs some rooms and beds. Usually I just manage to supply my starting 7 when the first migrants arrive.
Then I shift the miners to cut the real trade depot tunnel, as I want it nice and long. Somewhere in the process I also expand the courtyard with a fairly short trade depot approach (see previous post), decked over and with a dog guard house on top (if I'd deployed a dog already he's moved), an additional drawbridge, and 1 -3 cage trap arrays.
All of this will have to be adapted and adjusted to topography, geology, wildlife, and starting team special strengths, and, of course, be totally changed to suit the chosen play style.