I found that with natural fiber diapers, the pre wash and extra rinse were unnecessary since cotton etc wash so clean. We just do a warm whites wash. If you have trouble, add them, but I like to keep things as simple and short as possible. Start by using half the recommend amount of detergent and tweak your routine as needed.
Â
For a newborn doing prefolds you need
30ish infant prefolds, organic since they absorb more (higher quality cotton). The 5-15 lb size fits most newborns well. More or less depending on how often you want to wash. You can find these used if you ask around. Your old diaper service may sell their worn ones. Bummies is on good brand, though there are several others. Avoid Gerber like the plague.
3-6 covers. We used Bummies and Thirsties and if I need to buy more I would get Thristies Duos for the wider weight range (they really do fit the full range). Three covers minimum, but life is far better with six.
Wipes. I like single thickness cotton flannel wipes about 8" square. Easy to make, easy to buy, always inexpensive. one and a half times as many wipes as diapers minimum.
Pail liners. Not strictly necessary, but far nicer than washing the pail out. Planet wise and Wammies are great brands. You want two, one in the pail and one in the wash. Other people do large hanging wet bags with zippers etc.
Laundry Detergent. From the grocery store Arm & Hammer Essentials unscented worked best for us, and it has the fewest fragrances, dies, enzymes, optical brighteners etc. We use Country Save, which has non of those and is very economical when bought in bulk from Amazon. I am also just trying out Rockin Green.
Hemp doublers are nice for overnight when you get longer stretches of sleep. You can also just double up on the prefolds.