Just getting it to turn is easy. Getting it right is hard for a few reasons:

First, instead of the first derivation of direction like a steering wheel in a car the stick/yoke of a plane actually controls the second derivation of the heading, meaning that pushing it a bit to the right not only causes a turn to the right but it will turn right faster and faster. So you steer by pushing/turn the yoke a bit to the right/left and wait until you reached your desired turning rate. Then you move it back into neutral position and wait until you (almost) completed the curve. Then you do push it to the opposite side until your plane is level again.

Second, there's not only the rotation along the vertical axis (Yaw) to consider: You also have Pitch (nose up/down) and Roll (rotation along longitudinal axis). What you actually did by pushing the stick to side was rolling the plane which in turn causes it to make a turn because the lifting force of the wings doesn't point straight up anymore but a bit to the inner side of the rotation. So you loose a bit of vertical lift which you have to compensate for because gravity is still the same. To generate more lift you either have to change your angle of attack or your speed. The second can be done by giving a bit more throttle but chanigng the angle of attack is trickier: Your plane hangs 'sideways' in the air so you need both the yoke and the pedals to get it right.

Third, because the plane makes a turn the outer wing is a bit faster because it has the longer path (sadly, there aren't any differentials for wings) and because it is faster it generates more lift. Yet another force to account for.

And the forth thing that comes to my mind (which applies more for gliders than for motor planes): To fly efficiently (and for other obvious reasons) you don't want to fly in another direction that your noise points at. Eg. you want the plane's longitudinal-axis be tangential to the turning curve. In a car this would be equivalent to skidding and is rather easy to avoid but air offers a lot less friction. Think of driving around in a hoovercraft...

Now a landing is trivial: as long as the debris is scattered in the direction of the runway it's considered ok.

I can't see how that's the case. The author indicates that it takes students a good amount of times to do turns correctly, which means: not losing (much, if any) altitude, not overshooting / undershooting the desired compass heading, using the correct angle of bank that's both comfortable and not risking stall, all while keeping a look outside for other airplanes(assuming you're not relying on instruments).

Landing incorporating all of that to set up and execute the pattern, as well as keeping the airplane at a certain airspeed(too fast and you'll land too far down the runway, too slow and you'll stall & crash) and staying aligned with the runway to make sure you actually land on it.

FYI, I'm a private pilot with nearly 200 hours.

At the very heart of winged flight lies the banked turn, a procedure that by now seems so routine and familiar that airline passengers appreciate neither its elegance and mystery nor its dangerously delusive character. The author, a pilot, takes us up into the subject - http://www.theatlantic.com/past/docs/unbound/langew/turn.htm

Former student pilot here: you literally spend countless hours on "coordinated turns" which involve proper use of both roll and yaw controls (ailerons and rudder). It's much more difficult to do it properly than most people think.

Also, I would describe landing a small plane--and I've heard others describe it this way--as a "controlled crash." You are basically stalling the thing on top of the runway.

I would disagree. Not many people die from a bad turn unless you stall/spin.