You should look into ODJFS. If you want to make a decent amount of money, you should look into getting your home licensed. Action for Children helps with this.
The amount of children you can have depends on A) If you are licensed B) The age of the children you have C) The amount of adults you have there at all times.
If you are going to have younger children, you need to have different areas for them. I believe you need to have areas of the house that are just for them. You need to have cribs for children under 18 months or cots (maybe beds) for children over 18 months.
Look up the licensing rules and regulations for Type A and Type B homes. ODJFS and Action for Children are great sources for helping to get your started.
Good luck!