Take a look at this short video where I demonstrate splitting wood with an axe, firstly using a stump to split onto and secondly splitting a piece of wood on the ground. This video can be viewed in conjunction with this post that describes various splitting techniques (written 5 years ago, where does the time go!). Also take a look at this post on axe safety.
We teach these splitting techniques, and much more, on our Axe Workshop. You can see photos from this and all of our other courses on our Facebook page.