The Kettlebell Swing
Below is a video demonstrating the Russian kettlebell swing with key points added into the video. Hip hinge patterning drills are important for properly enforcing the hip flexion & extension required for the kettlebell swing. The hip hinge is extremely important, if at anytime you feel pain in your lower back, it is because you are not properly executing the hip hinge, and you are hinging at the lower back. Stop, and practice the patterning drills listed under "Patterning the Swing" section.
Once you feel comfortable with the hip hinge, you are ready to move on to the kettlebell swing, as demonstrated on the video above. Below is a video with numerous variations to the kettlebell swing, including the two handed kettlebell swings, single are kettlebell swing, and alterning kettlebell swing.