Man, there is nothing hard about nitro engines & tuning - they are a 2 stroke, just like their larger petrol powered cousins.
2 needles - 1 x for flat out (tune this one first) high speed needle (on nitro's, you ALWAYS want to see smoke coming out of the exhaust, even at full revs/speed)
the other - low speed needle is more finely tuned - all you need is an ear that works - most of us have 2
the low speed needle firstly sets the idle mixture this stops the engine from "loading" (getting RICH at idle)
If your idle "gap" is set on the carb, then you'll hear it speed up at idle as you lean it off, back off here (richen) until you think the idle speed drops again
(you can always run a slightly faster idle wit the radio if you're not sure)
tuning the low speed needle isn't hard
finer tuning of this needle gives the hole shot we all seek
usual thing is the "20 second test"
once the needles have been set, let the model sit and idle for 20 seconds - then GAS IT!
If it flares out, it may be too lean
Always go richer first, you can't hurt your engines that way
No point tuning ANYTHING until the engine is up to running temp.
If it's cold, then you're wasting your time
Once it's set, you'll find the engine (after priming - NOT flooding) starts first go
I see so many people at the track pulling like a bas*#@+d on the starter cord - usually tearing it out

this can be easily avoided

Tune it well,
stay on top of glow plugs
ALWAYS use after run oil (it may be days before you use it again, that's cool, but if it's months, nitro separates into water & acid) - that eats needle surfaces

Also, old nitro turns to jelly, and blocks up your needles/banjo fitting at the carb

hope this helps