Secondo me si potrebbe semplicemente dire così... Magari lasciando l'espressione fra virgolette anche in inglese, così si specifica che non si tratta di una vera e propria lezione, come mi pare di capire dal contesto da te fornito, ma piuttosto di una sorta di presentazione, di introduzione al mondo dell'equitazione.

for novice riders the first time they mount a horse
may render the colloquial term in Italian

How to Mount and Dismount a Horse Properly: 14 steps - wikiHow
www.wikihow.com › ... › Categories › Pets and Animals › Horses › Riding4 Sep 2011 – This way, you do not have to jump across to get onto your horse. 3 ... How to give a leg up: Stand as if you were about to mount with a mountin

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Note added at 2 hrs (2012-04-05 12:38:52 GMT)
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after thinking about it, other alternatives:
novices are given the opportunity to take their "first taste of the saddle"
even novices can "get to grips with the saddle"

Eg:
Getting Ready for Horseback Riding: First Time in the Saddle ...
voices.yahoo.com/getting-ready-horseback-ridi... - Traduci questa pagina
11 Aug 2007 – So you're ready to begin horseback riding. Good for you! Of course, you will want to begin with a few lessons before you head out on the trails ...