the method i use is, once my seeds have popped (if i didnt start them in rockwool) i put them i in the rockwool cube (tap root facing down) and the cube in a small dish under a fluro (20 hours light per day) with about 1/4inch of water in it... as it dries out every day, each evening it gets a wee bit of water
and blammo, spoutlings.. then when the roots come out the bottom, its time for a pot and soil, i use 4inch pots first off... soil is 50% perlite and 50%.. and leave about 1/4 inch of the cube sticking out the soil... no fertiliser/nutes.. easy