First I'll start with... I respect the opinions of both of the previous posters. And yes, they are both correct. In fact, take two elements of adamjh3's post "Number of Patients" and "Additional Resources" and add them into your Scene Sizeup if you want to slightly impress your proctor. Just be sure you don't screw up later and can back up that initial impression.
But NYS is a whole different beast in how it does practical exams, because you have to do certain things in a certain order or you fail.. -_- Since taking my original Basic, I've assisted in Practicals every year since, so I can give you a little heads up into it.
First, are you taking it at a NYS academy, or a local college/fire hall? If it's the former, you have to be VERY on top of things. If it's the latter, you tend to have a little more leeway, but should still be on top of it, as you never know when your proctor will be a stickler and when they'll let some things slide.
To answer your question...
Technically, the correction of life-threatening conditions happens immediately upon finding them during the Initial Assessment. If you're doing ABCs and you find the airway is open but they aren't breathing, you stop at "B" and bag them.
Look here to follow me:
http://www.health.state.ny.us/nysdoh/ems/pdf/emtpse08-06.pdf
You start with your Scene Sizeup. Annouce you're wearing BSI, ask if the scene is safe. It always will be. (lol) Assure that it is only one patient (always is), ask for your MOI. They'll explain what happened. If necessary, state the need for C-Spine and ask if you're on a Medic Rig. They'll say No, and you call for ALS if necessary. If you say "Call for a helicopter and set up a landing zone" they'll normally laugh at you.
Next, ASK THEM what your General Impression is. They should tell you what you're looking at... Ex: A male flew off his motorcycle and is laying in a field on his back with his one leg at a weird angle and blood from somewhere. All you do is repeat it, add whether you think it's good or bad, and what you're thinking of doing so far.
Now talk to your patient. If they answer, ask what hurts/what happened/etc. If they don't answer, try pain. Usually they answer to pain at the least.
Now ABCs. "Is my patient breathing?" (Usually yes) "Is my patient breathing adequately?" (Usually yes) "Is there any notable airway obstruction, or the chance of a future obstruction?" (Usually no) "I place my patient on O2 15LPM via NRB" (I dont agree with it, but per the state, you have to say it. -_-)
"Does my patient have a pulse?" (Always) "Do I see any major or obvious bleeding?" (If so, have your partner plug it) "How does my patient's skin color and temperature look?" (
THIS IS IMPORTANT. It is a critical, and what fails people the most, I find.)
Then you give your transport decision. Usually, if it's anything to do with ABC compromise, you transport immediately and do a rapid trauma assessment as you place them on a longboard. If it's something localized and you haven't had to do a lot yet, you can do a focused assessment. However, I've never seen a student say "load and go, do the rest in the rig" and be faulted for it by a proctor.
If it's a major trauma, VERBALIZE making them naked. (

) Do head/face/neck. Chest.. Look, listen, poke at it. Rock the pelvis, feel down the legs, check PMS. Go back to the uppers, check the arms, PMS. This has just checked your PMS pre-boarding, and you're back in position to take the trunk. Roll, and CHECK THE BACK before you place on the board. Be sure to verbalize it too, nice and loud. It's the most missed part of assessment, I find. Now, clip them in, make them squeeze your hands, tell them to wiggle their feet, and you're done. Verbalize a SAMPLE and OPQRST during transport, and you won't even need to remember the questions.

As for DCAPBTLS, LEARN IT. If you say it, a good proctor will call you on it and ask what it means. Don't embarrass yourself. haha
If you get lost, don't panic. Just start over at ABCs, and go from there. If you're still completely stumped or overwhelmed, make sure you get through your ABCs, say you're transporting immediately, give O2, and you've atleast covered your criticals.
The station gives you 15 minutes. Entire time for Scene Sizeup, if done properly, is less than 2 minutes. ABCs, unless you really have a screwed up patient, are another 2-3 minutes, and you can usually do the rest in 5 minutes. I find a well-prepared student can do the whole station (by memory) in about 7-10 minutes.