I found with the three I just hatched, they basically refused food for about 24 hours, and didn't have much interest in water, but I still dipped their bills periodically in both just to be on the safe side. I guess for the first 24 hours they are living off stored nutrients and water from the last of the egg yolk, and just don't need much -- I guess that's why they can ship newly hatched birds on a 2 day journey through the US Postal Service and Fedex in nothing more than a cardboard box with a little straw.
Temp and Humidity -- do you mean for hatching, or after? For hatching, should be about a degree cooler than during incubation, and the humidity should be about 65%, maybe a little more. After they hatch, about 12 hours later after fully fluffed, they should go into a brooder at around 95 degrees, and then the humidity doesn't matter, whatever the ambient moisture in the air is.
Male or female -- well, depends on the breed. Pilgrims and a couple of other really rare breeds (West of England Geese?" exhibit sexual dimorphism, so the genders can be told apart at hatch -- sort of, I found that my male Pilgrim didn't look nearly as different from the 2 females as I thought based on written descriptions, but after some further research I did learn to recognize the difference, it's just more subtle than I thought it was. But, for most breeds, I gather it's quite a bit harder to sex them.
I don't know how long the parents wait before taking them in the water, but whatever they do should be the right thing. For hand-reared, its probably safe after about a week to 10 days in nice, tepid water. My oldest gosling was 2 weeks yesterday, and despite how hard I try to keep her and the brooder clean, she is always messy, and I think I'm going to try to put her in the tub tomorrow in a couple of inches of water and hope she will learn to bathe. My other 2 are 8 and 4 days old now, so I'll wait on them. Honestly, I thought nothing was more messy than ducks, but geese are worse -- they seem to fling their food out of both sides of the beak as they eat.
Good luck, I hope it turns out for you. The hatching phase is the most nerve wracking of the entire incubation process.
