Why Do It?
My guess is one or more of the following is true for you:
All jokes aside, the above all ring true for me - I find cloth diapers to be a huge cost savings, I do like the environmentally friendly aspect (although not so much that I won't use disposable diapers when convenient), and I don't mind laundry all that much (more on that below).
So if you want to explore cloth diapers, that is exactly my suggestion - Explore. Don't spend hundreds of dollars on new diapers and accessories, but get a few different kids (used if you can!) and see a) do you even like cloth diapering and b) what do you like/dislike about different kinds of diapers before you go and buy 50 of them (and I really hope you don't actually buy that many, but I know for some moms it becomes a bit like an addiction (my sister has a suspicious amount of cloth diapers...)
I'm not going to go do research or go into intensive detail - if you want a great overview, I suggest babygearlab's Cloth Diaper Overview. I'm only going to share my experiences, and the thoughts I have on the cloth diapers we are using.
How Many Do You Need?
Short answer: I have no idea. It really depends on how often you change your kid (I err on changing cloth diapers at least every two hours to prevent diaper rash, which we had with our first kid), and how many days you want to go in between washing. With our twins, we could only go a day and a half before we'd run out of cloth diapers. We eventually got a lot more thanks to my sister sending us a full box of diapers from her kids, and a friend dropping off another huge box from her son. Now, I think we could go four days if we needed to, but we found out immediately that if you tried to do 3+ days of cloth diaper laundry for twins at once, it didn't get clean very well. So now it's every other day, but the nice part is, since cloth diapers often need to line dry, it's not a rush to get them dried, and stuffed or folded back upstairs asap, so it gives us a bit of breathing room. If you do choose to cloth diaper, I do suggest shooting for 2.5 days of diapers, but how many that is will vary by family.
I also will suggest starting with a smaller number, and with different kinds, then you can purchase or try to find more based on your preferences. But before you blow the bank on one kind of diaper, keep in mind what fits great when they are a newborn may no longer fit as well once they are older. My sister had a bunch of Bumgenius diapers, which were great when her son was a newborn, but now that he's 1.5 years old and tall and thin, they no longer work for him.
Below are my thoughts on the diapers we have at home. I do suggest trying multiple kinds out before you go all-in. Unless you find a great deal on used or free cloth diapers - then it's probably worth it as these can be expensive! Please note that I've found all of these get the job done - so it's more a matter of preference.
Other Recommended Gear
In addition to the diapers themselves, you may want to consider some other things to make this process easier. I have links below, but if you can find these used or from a buy nothing group that's even better. Also, you may not find you need all of these things, so you may want to wait to see how things pan out.
Cloth diapering doesn't need to be an all of nothing endeavor. We use disposables at night, and when we are going out in the car. So don't feel like you need to commit 100% to make it worth it. It's also fine if you do it for a while, and then take a break. My thought is given the cost savings and environmental impact, it's a worthy endeavor, but so are about 1,832 other things we can do as parents, so it's up to you to choose what you want to do.
*Please note that some of the above are Amazon affiliate links. As an Amazon Associate I earn from qualifying purchases.