Ducks are actually very simple to keep- but you can make things as complicated as you like. I have never owned a book on raising ducks - and know that they can all differ greatly- so which book do you believe?? I prefer to speak to other breeders either in person or online about issues, and have learned fropm their experience as well as my own over the last 25 years.
Basically- ducklings need food, water and heat in a clean environment. Once grown they need a predator proof living area- food and water. You can "puff things out a little " from those basic requirements.
Food - Ducklings needs are different from an adults- the type of food you give yours will most likely be determined by what brand you can buy locally. Some people do add suppliments to the diet- but in most cases if you buy a complete feed- you shouldnt need to suppliment.
Water - Ducks need water deep enough to get their head into to clean their nostrils and eyes- they can be messy. Ducks also like to swim- but dont need a pond. Even a container 1 x 2 foot by 1 foot deep in enough for them to have a wash in.
Warmth - ducklings require some heat when hatched- but depending on what age you get they may only need it for a short time or only at night. The tyype of brooder set up you will need will also depend on how old/ how many and what materials are available to you.
Housing - some ducks can fly and need to be kept in a pen with a roof- others may only need an area with low fences to be confined- The pen area will depend a bit on the breed of duck and how many you have.
The most important thing to know before getting a duckling is they are absolutley gorgeous- and you will soon want more after experiencing raising them for the first time