aout 1,2,3 cm or half an inch or so
make sure its before the seed has popped off(thats just what i think)
get the soild ready, i use 4:1:1 ratio potting soil,perlite,vermicultite
then water the pots until it drains out the bottom
next stick your pinky about 1/2 to 3/4 down in soil put taproot facing down
it can be a little tricky because its so small but youll get it
then pack back up the hole with soil and put under CFLs to start vegging should see them pop out of soil within a few days