I need to find on a map the north middle latitude and the south middle latitude

Answer 1

http://www.navis.gr/marinav/latlong.htm
Scroll almost all the way to the bottom and read the section called "Special Lines of Latitude and Longitude." Read carefully, and then find a map or globe on which you can find these middle latitudes. It's not difficult.

http://www.public.asu.edu/~aarios/resourcebank/maps/page9.html