K.S.
Hey K.,
Since you asked about being a nanny OR childcare provider. Not sure which info you really need more about.
But as a daycare provider in your own home, you are expected to pay all taxes. As some one who works in anothers home, the employers are expected to pay your SS and maybe some other stuff. Withholding taxes optional, when I was a nanny I paid my own "taxes".
I can't find the good site for information right now. But I did find one somewhat useful if you're a nanny or for someone who would be looking to hire one.
http://www.enannysource.com/nanny/employer_tax_faq.aspx
Hope this helps, K.