Illusion covered everything I wanted to say except that I would recommend you place your seed no more than 1/4" into the rockwool (I actually do it about 1/8". This will help germination and give the roots more area to grow into. If you are using the starter blocks with the holes already made, I wet the entire block, rip off a piece from the outside and wedge it into the hole to create a more shallow hole. Place your seed in with the taproot down and rip off a little more rockwool to cover the seed in the hole.