After "What came first, the chicken or the egg?", this is the second-most frequently asked question around here. No, seriously! What you're going to get here is 100% pure, unadulterated opinion (the best kind, mine!), so listen up! Pay attention! Take notes!!!
There are no hard-and-fast rules, believe it or not, just general guidelines. Different things work for different babies, and everyone who uses cloth diapers has different goals, be it cost, trimness, cuteness, or whatever.... So here goes... buckle up!
At the bare minimum, when buying cloth diapers for a newborn baby, you are going to need 12 diapers, that would be enough diapers to see you doing laundry every day (the horror, the horror!). If you're using pocket diapers, you will need 12 pocket diapers and 12 inserts since the entire diaper is changed with every diaper change. If you are using prefold or fitted diapers, you would need about 2-3 covers for every 12 diapers since you only change the prefold or fitted diaper with every diaper change -- if a cover is clean, it can be reused. If you're using prefolds, consider a Snappi or two, excellent for containg messes!
Once the baby stops pooping so frequently (expect it to slow down to 2-3 poops/day around 6 wks of age), that same 12 diapers will last you 2 days (expect to use 1 diaper overnight, then 5 changes through the day).
Basically, anything above and beyond 12 diapers is up to you. How much do you want to spend? how often do you want to do laundry?
When diapering a newborn baby, you really don't need doublers to add absorbency -- since baby will be pooping every 30 seconds (kidding! Well, sort of...), absorbency isn't so much of a concern in the first few weeks. What you need is something that will contain the explosive, runny newborn poop that you will soon become very familiar with. A fitted diaper will do well to contain newborn poop, or a Snappi-ed prefold will work well.
You really only need to start using doublers once baby stops pooping through the night. Doublers are typically used to increase a diaper's absorbency overnight. Around 4-6 weeks, baby will stop pooping through the night (hallelujah!), you'll still likely be feeding baby, but there's no need to keep changing baby once s/he isn't pooping at night. So you stuff baby with doublers. Maybe one, maybe 2, you'll figure out what works by trial and error. Hemp doublers are a good choice because they are trim and absorbent. Fleece-topped doublers are also a good choice because they keep baby's bum dry, so if your baby is prone to rashes, you may want to consider stay-dry liners. Although to be honest, wetness isn't such a terrible thing, air still circulates better in a cloth diaper than in a disposable diaper, and my kids have never had a problem, but as I've said earlier (say it with me!), "Different strokes for different folks".
As far as the number of doublers you need, count the number of days you can go between laundry... if you can go 3 days between laundry, that's 3 nights you need doublers for... makes sense, right? You may also want some extra doublers on-hand for those times when you won't be able to change baby as frequently as you normally would (ie -- a long car trip, or a long nap).
When you've made it through what professionals refer to as the "pooping every 30 seconds" stage, you are ready to tackle night-time diapering. We've already covered 'doublers 101', but there's more!
Wool covers are an excellent weapon in the war against night-time leaks. Wool covers do double-duty in the sense that they keep baby's pyjamas, sheets, etc. dry, while they also add absorbency to a diaper. Fantastic, no? Wool can absorb up to 30% of its weight before it feels damp. Wool is also an excellent night-time cover because it allows air to circulate -- great if your baby is prone to rash. When your baby is in a diaper for 10-12 hours, breathability is a good thing!
When it comes to wool, you'll want at least 2 wool covers. Why? Because wool takes so long to dry. When it comes time to launder your wool cover (about once every two weeks, or when it's soiled with poop), you'll want a backup because it will take about 2 days for the washed wool cover to air-dry. Some people also like to rotate wool covers -- use cover A on Monday, then cover B on Tuesday, then cover A on Wednesday then, well, you get the picture.
What kind of diaper you are using will determine what kind of wool cover you can use. If you are using a fitted diaper or a Snappi-ed prefold, you can use an Aristocrats soaker, which is a pull-up style cover. If you want to use a prefold folded in thirds, consider using a Loveybums covers, which is a wrap-style covers.
Most of our customers use hanging waterproof bags to store their diapers. They can be hung from a doorknob, a hook on a door, or the change table, they fold up small (great for traveling), and since they are always washed with the diapers, they don’t get stinky.
If you would prefer to use a plastic pail, you don't need anything fancy -- just a container with a tight-fitting lid (a ‘multi-purpose’ pail found at most department and grocery stores will do the trick). Some people use garbage cans with flip-up lids, some people use real, live, bonafide diaper pails with locking lids and deoderizer clips. If you are using a wet pail (not necessary), you *must* use a container with a locking lid, a wet pail is a drowing hazard. If you're not using a wet pail, but you have a nosey toddler, you may want to consider a pail with a locking lid all the same.
If you do choose to use a plastic pail, it’s a good idea to line it with a wetbag, if you're using a super-fly front-loading machine, the bag makes it easier to get the diapers out of the pail and into the machine.. Using a pail liner is also a good idea if you don't want to bother cleaning out your pail periodically.
When you're 'out and about', you can use a plain-old grocery bag to tote dirty diapers in, or you can use a wet bag to store your dirty diapers, it's a matter of choice... say it with me, "Different strokes for different folks!".