Hi
Google for ST7920.pdf. It will give you all required information:
Connect
PSB to GND
RS (chip select) to pin 2 of your Arduino
RW (serial data) to pin 3 of your Arduino
E (serial clock) to pin 4 of your Arduino
Then use:
U8GLIB_ST7920_128X64 u8g(4, 3, 2, U8G_PIN_NONE )
Of course you could use any other Arduino pins also.
Oliver