Let's see...goose care 101
*Feed- I use an all flock pellet made by Nutrena, but there are many different brands that offer it. Any of the all flock/flock raiser is what you should look for. This time of year when grazing is at a minimum, I've been keeping an eye on the clearance produce. Anything green is a fave of the geese.
*Water- Constant supply, deep enough to dunk their whole head. They enjoy baby pools to clean themselves also.
*Shelter- Mine roam all day and only use their beds at night (sometimes). However, depending on your location and predators, it's a good idea for them to be locked up safely overnight. The biggest concern with any waterfowl housing is that it stays dry.
That's a very broad, general overview of it...any particular questions would be easier

We've got a lot of great goose people here so don't hesitate to ask..and share lots of pics!!