I don't know about geese, but we do have ducks. I've found Dave Holderread's
Guide to Raising Ducks really helpful.
Boondockers Farm also has a really helpful overview on raising ducklings to ducks:
http://boondockers.sharepoint.com/Pages/Raisingducklings.aspx. I'd read this first, then move on to Holderread's book.
I also end up using
http://www.majesticwaterfowl.org/ a lot. Their site is often a little difficult to navigate, but they have a lot of good information, especially on diagnosing problems/illness/diseases with ducks (and geese, too, I believe).
And, of course, I use
http://www.backyardchickens.com/f/ a lot. One thread I refer to a lot on there is
The ULTIMATE list of DUCK Treats and Supplements.... This is really useful for knowing what I can feed, as well as should not feed, my ducks.
I also ferment my duck food, and so refer to
Scratch and Peck'sinformation on it quite a bit:
http://www.scratchandpeck.com/wp-content/uploads/Fermenting-Feed_7-27-2015.pdf
I find myself at
Metzer Farm's site, too. They have some good information on how much each breed of duck lays, how much light to supplement (if you want to go that route), and how much feed to give your ducks.
I hope that helps!