Do they get light?

I got a setup that I've based off of Mr. Green's. In his video he put the seeds in the rock wool plugs as soon as they crack. He then stores them in a dark spot until they sprout through the rock wool, from there they go under lighting. My question is this the most preferred way of doing it? Is it better to throw them under lighting once the seeds crack and you put them in the rock wool cube?

Makes no difference if they get light until they break the surface of the medium. As soon as they shoot through the surface hit them with some veg lighting.

Some people wait for the seedling to stand upright with its leafs facing upwards.

The seedling will stretch upwards in search of a light source, so by cutting off the light it will usually become upright faster.

It's up to you, in that early of the stage unless you STRETCH it out really bad doing what you said is fine.

Sounds good. Thanks for the tip.