Hi Sigma, what engine is iot that your running???
Do not start it until you know that the HSN(Highs Speed Neddle) and the LSN(Low Speed Needle) are set nice and rich, which means your engine will be using lots of fuel for the run in(Break In) or you will probably end up killing the compression.
If you can give us the make of engine you are using we can help you alot more as each engine has a different setting for the needles and what glow plug your intending to use.
Normally speeking these engines can take alot of punishment but when they go bad, they really dont want to start anymore.
TDC and BDC means Top Dead Centre and Bottom Dead Centre, when you've finished driving your buggy it's best to set you piston at Bottom Dead Centre so that when it cools down the metal will shrink and you'll keep compression longer(Very Important).
There are forums here on RCU where people have asked the same question as you. You'll find them in the engine section at the bottom of the page.
You could try warming up your engine with a hair drier befor you try to start it, this does help a bit.
Your local hobby shop guy is sending you on a track to destruction as far I'm conserned so that you screw it up and have to buy a new engine, beleave me, when I started out my local hobby store did the same.
Destroyed 2 engines following there advice untill I managed to find some one also in the hobby. Helped alot. been at it now for almost 25 years and still running strong.
Good luck for tomorrow, it'll be fun and noisy (and smelly).
Try not to be scared when it fires up.
Like 378 already said, look in your owners manual for the settings and you cannt go wrong.
One last thing,chech the opening of your carb to make sure it's not open to much other wise your buggy is going to just drive away on it's own and beleave me, you cannt run that fast, I've tried.[:@]