You can claim the amount paid as child care, provided you paid your nanny so that you could work and/or go to school. You are able to claim the amount paid to the nanny plus the employer expenses (employer paid CPP, EI). You can also claim the amount paid to prepare the payroll. However, there are maximums that may be claimed for Child Care so the total of all these amounts may be moot, as they may exceed the total that can be claimed.
http://www.cra-arc.gc.ca/tx/ndvdls/tpcs/ncm-tx/rtrn/cmpltng/ddctns/lns206-236/214/menu-eng.html