Hi
We have kept ducks for a number of years. I always believe the first thing you want with any animals is for them to be friendly. We have found with ducks that if they have not had regular contact with humans, or have been mistreated they become very skittish, and it is a big problem to make them friendly again. So make sure you get happy friendly ducks.
All ducks, particularly big ducks make a right old mess when it is wet, smaller ducks can make a right old mess but on a smaller scale. On the smallholding the big ducks had access to the fields and garden, and use to often flatten the smaller plants in the garden.
All ducks need the opportunity to bath, a pond is ideal, but some breeds will do with just bathing water. They do make the water very messy very quickly, so changing the water regularly is important. They also need space and don't like being to crowded.
Ducks can be noisy, so you need to think of possible neighbour problems.
Looking after does not require a massive amount of time. Feeding, cleaning run, and changing the water are the main jobs.
What types, Khaki Campbells are generally the best egg layers, we also found that the American Pekins were not far behind egg wise, and are my personal favorite, of the larger ducks. If keeping in a pen I would only keep one drake with several females, otherwise the drakes will fight.
We now have call ducks, which are much smaller and can free range without causing any damage to the garden. They are good for snail and slug control, but the eggs are really too small to eat, and they are not prolific layers, although people do buy the ducklings to keep in their gardens, details of their needs are on my website.
We would not be without our ducks and do enjoy them being around.
A good book on ducks is
The New Duck Handbook ISBN no. 0-8120-4088-0, which I am sure you will be able to find via the link on this site to Amazon, or John may be able to confirm if it is available via Katie Thear.
If I can be of any more help let me know.
I take it the hens are ok.