You have decided that you're more of a duck person and want to start raising ducklings. Well, lucky for you I'm here to help.
I recently purchased 2 ducklings from the market a week ago. They were already 2 weeks old, and so my guide will start from that age.

At 2 weeks the ducklings do not need a heat lamp anymore,but still need to be kept warm. I provide warmth using soft hay and thick bedding inside the duckling enclosure, then put them inside the shower with hay and food/water at night.

The enclosure: In order to keep your pets safe, happy and secure, you need the proper housing. A place for your ducklings to have room to walk and be safe from predators. A duckling enclosure should contain a sturdy shelter. This can be made from a wooden or plastic box, or wolden planks positioned in a tent shape. It should enable your ducklings to get out of the rain, wind and have a place to sleep. The enclosure itself should be made of wire mesh, or good fencing, it doesn't matter what shape as long as predators can't get in and ducklings can't get out. My enclosure is made of metal poles, with thick wire mesh and a little door. I have to say, the door isn't very helpful when trying to catch the ducklings/cleaning the enclosure. The best would be to have the top ( also wire mesh ) removable and to be able to lift it.
A dog run with a kennel is perfect-

At this stage, the ducklings still need food and water 24/7. You should give your ducklings unmedicated chick starter, which is relatively easy to find. Grit and/or raw oats can also be provided to help them digest their food and get more protiens. Healthy greens and treats such as dandelions, chopped grass, kale, peas and oatmeal are also great for ducklings. I find my spoilt ducklings don't like their lettuce to be dirty, so putting it inside the waterbowl or pond lets them scoop it up without it being trampled.

Ducklings need water to swallow food, so male sure they have a bowl of fresh water nearby. They will grab a mouthful of feed and dunk it into the water to help swallow it, and if they do not have water they can choke. For this reason, the feed bowl will usually be wet, so make sure it is thrown out and re-filled daily.

They should have a clean water bowl, and a pond or basin of water large enough for them to happily swim around. Make sure the feed and water bowls are heavy so that the ducklings cannot tip them over. Ducklings hatched in an incubator, unlike those hatched under a mumma duck, do not have oil glands working to coat their feathers, so they aren't waterproof. This means they can easily become waterlogged and drown. Until they are at least a month old, ducklings should have short and supervised swims each day. If your ducklings were raised by a mother duck, you can stress less for your ducklings are fine in the water. Do make sure they don't catch a cold though. I always dry my babies with a towel after they have had their swim.

Bonding with your ducklings is very important. You will find this much easier if your ducklings were hatched in a brooder because you were most likely the first thing they saw. They will think you are their mumma, and will follow you everywhere... litterally. This also makes it hard to get privacy.
The ducklings I own right now, however, were raised by a real mumma duck. This means I have to handle and pet them even more, otherwise they can become wild.

Take care of your ducklings, and they will become your best friends until the end.