matt gave some good info, i'd like to add to that.
>>When do y'all recommend I call and end to the investigation and decide it's male/female since I don't know the specifics?
since you don't know the gecko's age, you can go by weight. you should be able to loupe for pores and accurately determine gender by around 15 grams. it is possible to do this earlier if you're really good at it.
>>What mixture of CGD:H2O do y'all recommend?
1:2 - but add more or less water to your gecko's preference and how fast it dries out or molds up. it should be able to last for a couple days (you can remoisten on the second night).
>>How big of a serving is recommended for a young crested gecko?
i use a bottle cap about 1.5" in diameter and 0.5" high for small geckos. you could use disposable souffle cups but i find those get knocked over easily due to their light weight (i guess this wouldn't be a problem if you use the feeding ledges, i have never used them). you can mix enough food for a week or two and freeze it, taking each cap out to thaw the night of feeding. try to make an amount to where you can see the gecko has licked most of it up.
>>Exo-terra night bulb or an infra-red bulb?
your room temp is fine but if it gets really cold in the winter, you can use a low wattage (40-50 W) bulb. as long as the light is red or blue it's fine, some allow you to see them at night better, personal preference.
>>I've got a pair of the dial thermo/hygrometers manufactured by zoomed, Is a second set required or is this sufficient?
one set should be sufficient. i prefer the acu-rite digital ones with a probe for my permanent setups so i can get temperature readings from the top and bottom of the cage. analog have been known to be off by as much as 5-10 degrees.
http://www.usahardware.com/inet/shop/item/61220/icn/20-408195/acu_rite/00891.htm
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3.1.1 snakes, 3.1.1 crested geckos, 0.1 gargoyle gecko, 2.0 devon rex cats, 1.0 betta