Hold the recorder with the microphones at the top, and the big round button facing toward you.
On the front, there's only that one round button, which is record.

Left side, going from top to bottom:
Headphone jack
Volume up
Volume down
MicroSD card slot is behind the square panel.

Right side, going from top to bottom:
Line-in jack
Gain up
Gain down
Fastforward
Play/Pause
Rewind
Delete (slightly resessed button)
Hold/Power slider (push up to hold, pull down to power on/off)
USB connection

Switches on back from left to right, notated from the perspective of holding the recorder like normal:
Recording format (up is mp3, down is wave)
Auto level (up is on, down is off)
Low cut (up is on, down is off)