Hatching takes about 28-35 days, at 99*F, humidity should be 50-55%. They need to be turned 3 times a day.. Day 4-27 the eggs need to be cooled for 15 minutes and sprayed with luke warm water (simulates the mom getting off the nest to swim) At day 27 stop turning the eggs, and put them on lock down, raise humidity to about 75%..and wait lol
They should be fed non medicated chick starter(they can overdose quickly on the medicated feed) and be provided with fresh water at all times..The feed may feed to be supplemented as geese need niacin. This can be done by sprinkling brewers yeast on the feed. It should be supplemented for 10 weeks.
They are messy babies, they can destroy a clean brooder in a matter of minutes if allowed to play in their water. Keep them on non-slick "substrate", don't want them slipping and sliding. And Spend LOTS of time with them, the more time you spend, the friendlier they will be as adults.
The rest is all about having fun with them!
take lots of pictures, they grow up fast.
Good luck with your eggs, I plan to get some more this year, but I will probably find them locally.
All of my info is from memory, I hatched goose eggs 8 months ago, feel free to correct me