The numbers on the far left column are the pressure levels (925 = 925 millibars, 850 = 850 millibars, etc.). This particular hodograph plots data from the surface through 100 millibars, but only lists the stats from 925 millibars through 100 millibars.

The second column are the heights, in meters, at which each pressure is found on this day. For example, one would have to travel 5,538 meters above sea level to reach 500 millibars of pressure.

The next two columns are the actual direction and wind speed found at those pressure levels (and heights). For example, at 700 millibars the direction is 160 and the speed is 34. This means the winds are from 160 degrees at 34 knots.

Here is an example of how the cardinal directions are defined.

Using the wind barb method, a wind direction of 160 degrees with a speed of 34 knots (rembember, put the direction and speed together and you have the wind velocity!) might be shown like this

On a hodograph, it might look like this, or you can add the wind vector. Notice the directions have changed on the hodograph. They are, in a sense, "backwards". The wind vector points TO the 160 degree position on this plot, but still represents and wind that is front the southeast! Either way, when ploting the wind vector, it shows the which way the wind direction is blowing from. It all depends on how you like to think of it in your mind.