I use a pre-mixed soilless mix that has fertilizer in it and have had no problems in the six or so years of using it. I do think the conventional wisdom would say wait until the seedlings are under the lights for at least a couple of weeks before adding a dilute amount of fertilizer. That would be the mix with water type (miracle grow or similar). As for worm poop, that I have not used but nutrients is nutrients.

The standard recommendation (there is a FAQ and many discussions here about this) is to not leave them to grow-on in the seedling germination tray. ;)

They need to be transplanted to new containers at least once to trigger the cellular change in the roots that leads to lateral, fibrous root development. So once the first set of true leaves develop, most of us transplant them (and plant them deeper) to larger containers filled with a soil-less mix that either contains some time-release fertilizer in it, OR transplant and begin feeding them with a dilute (1/4 strength) liquid fertilizer mix.

Those of us who do bulk germination in large seedling trays often transplant just after germination while still at the cotyledon stage.

Hope this helps.

Dave

Here is a link that might be useful: Potting up discussions...