Each region/city will vary in what is charged.
Keep in mind, that when you babysit other people's kids.... they will claim you on their taxes. Therefore, you need to claim the income on your taxes too.
Also keep in mind, that there are state laws on the ratio of adult to child. So if you have one kid, and you, then fine. But if you have say 4 kids and you, then what? You need to see what your city's regulations are, the business license requirements, what Providers need to do, have a fully baby/kid safe home, have liability insurance, contracts for the parents to sign off on, rules for things. if the parents bring their kids foods and diapers or if you provide that, the time frame, and if you charge hourly or a flat monthly rate regardless if they show up or not, absence/sick policies, a contract for parent to sign if you are "transporting" the kids in your car, if you are just going to babysit and play, or "school" them?
What ages will you babysit?
Do you have a crib? place for them to nap?
Toys just for the kids you babysit? Your own kids may not want other kids to play with their toys. It is best, if you separate... your own kids' toys from the babysitting business. etc.
Lots to think about.
If you are only going to babysit 1 child, then well, lots of SAHMS do that without any formal business license or provider certifications.
Do you have CPR or First Aid certification? Most parents want that.
I have done child care from my home, when my eldest was a toddler and before I had my 2nd child.
I did it for close to 3 years.