How do I get quarried stone?

Near any house plot in Skyrim Hearthfire there is a quarry in the direct vicinity of the house plot.

As example, for the house plot in Falkreath, the quarry is directly next to the construction bench. You just need a pickaxe to quarry it. Fortunately there is a pickaxe right next to it.

There are some other places too in the world, but I don't think it would make much sense listing them because of what I said above.

Quarries also provide an infinite amount of "Quarried Stone", so you don't have to go anywhere else.