Ducks are not usually sexed at an early age as they all peep at about the same level. It won't be until they are well over a month that you will notice the females starting to do a true quack and the males developing a couple of curly feathers on their tales.
Only feed unmediated feeds to ducklings as they have tremendous appetites and can be poisoned by the medications building up in their livers. In my area, unmediated feeds aren't available so I usually use a broiler feed for the first few weeks and then switch them to a lower protein feed to avoid "angel wing" from developing, you may even be able to get a waterfowl maintenance feed. As to water containers, I use a margarine or potato salad container modified like this:
to water them. It is deep enough for them to drink from and wash their nostrils out and helps lessen the mess they make as they shake their heads.
Ducklings shouldn't be allowed to swim unsupervised before they are feathered at or about 4 weeks of age as they won't have enough natural oils coming from their oil gland in their tail to water proof their outer feathers. Also, make sure that if you do set a pool of any type for them, that there is something they can climb on to when they want to jump out as it is possible for them to drown if they get too tired and they splash the water level too low.
To be honest, the only stupid questions are the ones you don't ask. As to sources on the web, there are so many of them. Doing a web search using Google and the phrase "raising ducks" will pull up close to 200,000 links. Several of these sites have awesome information on raising ducks and most have it in an easy format to follow.