The Edison Module has dedicated pins for an SD interface. In the following document you can check where those pins are located in the Mini-Breakout Board: The specified item was not found..
If you are looking for a schematic my suggestion would be to check the Arduino Expansion Board schematic since it already has the interface for the SD Card. You can take advantage of it and develop your interface for the Mini-Breakout Board. You can find the Arduino Expansion Board schematic here: Intel® Edison Arduino Board Schematic (pdf). Check the page 8.