This is a basic upper body strength movement that specifically helps develop the snatch.

Stand with the bar on your back like a back squat. Put your hands in your snatch width grip. 

Squeeze your shoulder blades together, midline braced and tight. Like a normal front rack push press, dip down then drive hard against the floor with the legs as you would for the push press or jerk to create upward momentum on the bar.  As the bar leaves the shoulders, continue pressing it with the arms straight up into the overhead position like an overhead squat. Lock your arms to support the press. Lower back down and bend your knees to absorb the lowering of the weight. If this is new to you, practice this portion often and with light weight until it feels smooth and coordinated. 

Experience Levels
The Snatch Grip Push Press doesn't seem very complicated but form and technique is essential especially in the dip portion, and also lowering the bar onto the bar for sequential reps. 

The more your practice the more experience you will get, there is no exact set amount of experience that makes someone a novice or intermediate. It's very individualized.

With that said err on the side of staying lighter then heavier if unsure. Refer to difficulty and equipment.

Difficulty and Equipment
This is not an absolute scale, but in terms of progressing in ability here's how you should be progressing:

  1. PVC Pipe.
  2. Empty barbell.
  3. Increase load as able.

Difficulty level will progress by adding weight.