Why Clicker Training Works
Dogs (and dolphins) live in the here and now and, unlike humans, do not dwell in the past or future.  For a dog to mentally link an action with a reward, the reward must be delivered within one-half second of the behavior you want him to learn and repeat.  Given a food reward five seconds late, in the dog’s mind there is no longer a connection between the action and the reward; he’s simply getting some food.

At the start of clicker training we pair a distinct sound with a food reward, allowing us to thereafter mark/reward a behavior in real-time, well within that half-second period.  The click comes to mean two things to the dog:  (1) “what I was just doing when I heard the click is something I should do more of because” (2) “a treat reliably follows.”

The Starting Point:  Conditioning Exercises
The initial “conditioning” exercises—which pairs the clicking sound with a food reward—takes about four days, with several two-to-three minutes sessions per day.  Using a small inexpensive ($3) plastic and metal noisemaker, all you do is click the instant your dog receives a tiny morsel of valuable food.  That’s it.  During each short conditioning exercise, the click/treat is repeated 15-20 times in quick succession.

Now you’re ready to pinpoint behaviors in a way that your dog clearly understands.  From here on out there is a lag between the click—marking the desired behavior—and the treat.  Every single click is always followed by a treat, even if it takes a few seconds to deliver.  In fact, the period between the click and the treat is a highly enjoyable time for your dog.  Like a kid before Christmas, anticipation is half the fun!  Think of the sequence as click-then-treat.

Nothing Lasts Forever
Folks are sometimes wary of clicker training at first.  Who wants to carry a clicker around forever?   Ah, but you don’t have to carry it around at all, let alone forever:  the clicker is used only during brief (five minute) training sessions when teaching brand new behaviors.  Once your dog is reliably performing an action on cue—a visual signal and/or a verbal command—the clicker is taken out of the picture, and then food rewards are faded.

For simple behaviors, you might just use the clicker for a day or two.  To teach more a complex (and highly useful) “chain” of behaviors, such as having your dog retrieve a beer from the refrigerator, the clicker is used to mark each step in the sequence.  Either way, by marking precisely the desired action in real time, your dog will learn twice as fast.  And once a step becomes second nature—he opens the refrigerator door just because it’s fun and pleases you—the clicker is retired.

One further point on the use of clickers:  I encourage my clients to give it a try.  If it feels like too much to juggle, they’re free to use food rewards alone. You can pick it back up anytime, say, when your puppy is a dog and you’re ready to teach tricks.  Dogs with clicker training under their, um, collars will remember and immediately respond.

Many Mini Steps on the Way to Perfection
In clicker training we often mark a behavior in a short form to develop one far more complex. Early actions are mini versions of larger behaviors, the clicker used as a scalpel to hone and refine. 

For instance, a dog lifting a paw to touch a cone is the beginning of a wave; a dog sinking its shoulders to lie down is the beginning of a bow; a paw touching an object is the opening to push, roll, flick, pick up, or rotate that object.

Referring back to the dog driving video,  you’ll see the trainers “shaping” the behavior that will eventually become the dog putting the real car in gear.  A mock-up of the gearshift is set on the floor.  At first the dog is clicked for simply touching the ball at the end of a stick. 

But over the course of multiple training sessions they up the ante, only clicking/treating when his paw stays on top of the ball/gearshift.  (The dog also gains a great deal of information from not hearing a click.)

Resources
You can find instructions and videos on the web for using clicker training to teach pretty much anything you can think of.  But the sky truly is the limit:  Anything your dog can (safely) physically accomplish can be taught via tiny increments, progress distinctly marked with the clicker, the ante upped until the end result is achieved.

Finally, the following is a video of Donna Hill clicker training to perfection a bird dog retrieving to hand.  This is significant because old-school training of gun dogs was particularly brutal.  This shows expert use of the clicker as a tool to shape a complex behavior, one gentle step at a time.