I’ll put together a drawing at some point soon for the Uno, Nano v3, and Mega, but the v3 should be the same as the Uno assuming you’ve flashed my firmware from Github.
RC522 PIN <–> ARDUINO PIN
3.3V <–> 3.3V
RST <–> D10
GND <–> GND
IRQ <–> D6
MISO <–> D12
MOSI <–> D11
SCK <–> D13
SDA <–> D9