Does it require any licensing? Depends where you live. You also have to know if you will have neighbors report you if licensing is required and you don’t follow all the rules.
How complicated is it to start offering neighbors to bring their children to our home to be babysat while the parent is working? It’s not that complicated but there are factors that one needs to consider. Is someone else already providing this service with a 1/2 mile radius? What ages will you baby sit for? Do you have the physical room for it?
What is the typical hourly or weekly rate charged for such a service? Depends on the neighborhood. Suburbs would probably be a higher rate.
Can a decent income be made from a babysitting / daycare service out of your home? Again, it depends on what you mean by “decent income”.