When your airplane has finished loading in X-Plane, press Enter for XPlaneNetworkData2 to begin receiving data from X-Plane.
Airspeed, heading, altitude, throttle setting, vertical velocity, and vertical vector will show.
Press an unassigned key (Q) on your computer keyboard to see what pressing computer keys 1 thru 0 and a few letters do.
Here's a lot more info:

The XPlaneNetworkData2 window disappears when it loses focus, but can be put back by pressing Alt-Tab.

A, S, H will turn on (and off) altitude, speed, and heading hold. Y turns yaw damping on and off. It's my autopilot (not X-Plane's).
The following numbers must be typed in on your computer's Number Pad:
Type in a heading number followed by D (e.g. 123 D (for degrees)). H will show.
Type in an altitude number followed by F (e.g. 2500 F (for feet)). A will show.
Type in a speed (in knots) followed by K (e.g. 150 K (for knots)). S will show.
Type in pitch degrees followed by P. The default is 5.
Type roll degrees followed by R. The default is 30.
You can enter a decimal number for pitch or roll.
Press the 9 key to see Pitch, Roll, and Yaw trim. And the correction to yaw (beta).

If you want to make less than 10 degrees autopilot heading change, a default divisor of 30 can be decreased to a
smaller number for fast planes, so try entering smaller numbers on the number pad and then pressing the   J   key.
The F-4 Phantom II needs a 1. Don't forget to go back to the default by entering 30 on the number pad and then J.

You can pre-program D, F, and K. Type in a number and then press CTRL-D, CTRL-F, or CTRL-K.
Then later you will only have to press D, F, or K for them to take effect.

You can change the speed ratio. CTRL-1, -2, -3, -4. or -5 changes it to 1x, 2x, 4x, 8x, or 16x.

Press  .  to pause/unpause X-Plane.

To help put and keep the plane on an arrival/departure route, press:
I   for the same vertical line that's used for an ILS.
E  for an extended route line (or runway).

To do any more, you'll have to create a new folder in Windows: C:\\Users\Public\X. This folder will hold any files you
create for XPlaneNetworkData2, AND you'll have to create sub-folders of that folder if you want to keep different
files separate.

To create destinations to fly to, after you've selected an airport and runway in X-Plane, and the plane's on the runway,
press the  1  key to open either C:\\Users\Public\X or the sub-folder of your choice. Add a new filename to the folder.
This will convert the plane's data to runway data and put the new destination's data in that file.

Press the  1  key again to see the name of the airport, the distance to it, and a small circle on the big circle indicating its
relative position (and with a line from it indicating the runway's direction). And, when you're on a final approach
to that runway, press the  3  key to see ILS cross-bars.

To fly a more accurate ILS, you'd need to select the opposite runway at that airport in X-Plane. This program will
use that data in combination with the first runway in order to use X-Plane's more accurate xyz 1-meter orientation
instead of X-Plane's latitude, longitude, and altitude. --SO-- when you're on the runway you selected by pressing   1  
go to Flight Configuration in X-Plane and put your plane on the opposite runway.
THEN in XPlaneNetworkData2, press SHIFT and the   1    key.
XPlaneNetworkData2 will then add this second location of the plane to the destination file for that airport.
NOW you can press 3 and then SHIFT (after releasing 3) to see the more accurate ILS cross-bars.

To help with aircraft carrier landings, if you add an empty file that you've created (in Windows Notepad), with the name
CARRIER.dta, to your destinations folder, and then select it as the destination, XPlaneNetworkData2 will show ILS
cross-bars that will take you to the #2 wire. The glideslope here is 3.5 degrees to make up for the 30 knots of the carrier.

To stop showing destination location data, add another empty file with the name EMPTY.dta to your
destinations location folder. Select this to stop showing that data.

To see VOR info, create a file in Notepad named VOR.txt and put it in C:\\Users\Public\X.
In that file, using information from AirNav on the Internet, write the name of the VOR, followed by its lat/lon.
For example, SANFRANCISCO 37.6194853/-122.3738936
NOTE that the lat/lon is copied from the lat/lon in parentheses.
Press   4   to select a VOR. It will show in a relative position as a small black circle on the big circle.

XPlaneNetworkData can show a full-screen map along with the HUD circle. Press   M   to show/not show it.
BUT you need to load an airport on the small screen first. Then when you go to full-screen,
you'll see that airport, the plane, and any other airports, VORs, or fixes you created.
Going to full-screen also will put the next fix (if there is one) on the small screen when you go back to it.
You can add any number of runways, VORs, and fixes to the map (create departures/routes/arrivals).
BUT FIRST, you'll have to create a folder named C:\\Users\Public\X\DeparturesArrivals to save the data.
You can add additional runways when on the full-sized screen by pressing   1
Press the right mouse button (without lat/lon showing) to place a VOR that you put in C:\\Users\Public\X\VOR.txt.
You can move the mouse over a VOR to change its radial or arc anytime.
Press the left button to create a fix at the mouse location. After the first fix, subsequent fixes have lines to them.
To measure distance & bearing, hold the ctrl or shift key down, press the left mouse button and hold it down.
Delete a fix by moving the mouse pointer over it and pressing the Delete key.

The data from this will be used in the small XPlaneNetworkData window as fixes or VORs to fly to/from.
Fixes/VORs will be shown in the order you created them (press space or backspace to change to another one).

Press the   3   key when starting an ILS approach to stop information from the full-sized screen from being shown.

If your plane is off the map, its bearing and distance will show at the top of the screen.

Scroll the map with the Arrow keys, and zoom with PageUp and PageDown. Hold the CTRL key down to change by 10.
Press   L   to see/stop seeing latitude & longitude at the cursor as you move the mouse.

You'll probably have to move and/or zoom the map to make lines from a VOR or the arc around a VOR show up properly.

The data is saved in a text file in C:\\Users\Public\X\DeparturesArrivals; so, if you open it in Notepad, you can change
numbers or delete a line or swap lines. But be very careful -- it's in an EXACT format. The one odd entry is northing2;
if easting2 is 0, then northing2 is actually fix distance in the upper 16 bits, and fix bearing in the lower 16 bits.

Since XPlaneNetworkData uses UTM coordinates (as well as lat/lon), you can't see anything in a UTM zone
that's not in the same UTM zone as the one your plane is in. BUT the small-sized screen still can show the
relative position and distance of anything you've chosen to show. Fortunately, each UTM zone is very big.
(search for "map of utm zones" on Google)

You can move a plane ANYWHERE in XPlaneNetworkData.
BUT moving it anywhere causes the plane's altitude to increase because the earth is round.

To move the plane, open the full-screen map, and press the MIDDLE mouse button (the mouse wheel).
The plane will try to go to the destination airport's altitude plus 5,000 feet when you press that button.
The move can be improved with subsequent presses of the middle mouse button at the desired location.

The middle mouse button also allows you to move the plane's heading or the plane's altitude
if you're not in full-screen and you press Ctrl when you press the middle mouse button.
To stop this capability, when you're not in full-screen don't press Ctrl when you press the middle mouse button.
The arrow keys move the plane.