How do I sign up to receive financial compensation while I care for my mother in her home?

I wish it were this easy. First of all, Medicare is unlikely to help, but in some states there are exceptions. Medicaid often helps some. However, each state is different (these programs are federally funded but state administered). So, try going to your state Web site. Type "aging" in the search and follow the local links for information. You will find the National Caregiver Support Program on the site (could have a different name). This can also be very useful. Good luck.
Carol