That's more important for "used" diapers. Though you are supposed to prewash them before baby wears them. I always washed (note the past tense-Nathan's been potty trained for a couple months, so no more diapers here!) them on a short cycle (wash and rinse) on cold without any soap. That was mostly to rinse much of the pee out of the diapers. Then a hot longer cycle (wash and rinse once again) with soap. Lastly I ran a second cold rinse to make sure all the soap was out. Then I hung them on a dry rack.

I used a dry rack rather than a line for a couple reasons. I could hang them on the rack in the house then move the rack outside. I found that much easier with a baby then trying to take baby and diapers outside to hang them. Also if it started to rain I could quickly run outside and bring the whole rack inside.

You will want/need to use the dryer every now and then. Actually it's good for your diapers to go through the occasional run in the dryer.

You'll want to look up how and when to "strip" your diapers too.