Interfacing a SD card to the PIC
SD cards can be operated in 'SPI Bus' mode - this uses 4 wires - CS (Chip Select, SD pin1), Clk (SD pin 5)and Data In (SD pin 2) and Data Out (SD pin 7). SD pin 4 is Vcc, pins 3 and 6 Gnd. For more information, see here
Note 'standard' SD cards run at 3v3, whilst the PIC runs at 5v. This means a voltage divider on the CS, CLK and DI lines (2k2 serial folloed by 3k3 to GND)
Actually reading and writing data to and from a FAT32 formatted SD card is so complex that a C Library is required