For an interdiction, you'll need the Frame Shift Drive Interdictor, which can be purchased at almost every space station with an outfitter. With the FSD Interdictor in one of your fire groups (I recommend your secondary group, fired with
) , go behind a ship in supercruise and in a pretty close range and interdict him/her. You'll need to keep your focus on the ship until the blue bar is full. When the blue bar has filled, you have performed a successfull interdiction (This also shows in the info tab in your ship). Repeat this until you have the achievement unlocked.
WARNING: Interdicting a non-wanted ship results in a fine and eventually a bounty if you assault the ship you interdixted.
Update 22-03-2016: Fixed a typo.