What to do after sprouting?

Ok, so I am completely new to the wonderful world of plants. So now I have begun to grow plants. Right now, I am growing catnip, I got some germination type trays from my local garden center and used the recommended soil for sprouting. 4 of my 9 plants have sprounted and are growing. They are roughly about an inch long and they are very fragile, they are still in the germination trays. What I want to know is, after they sprout, what do I do? Do I put them into a pot as soon as they sprout or do I leave them there until they are a bit bigger? Also, The person at the garden center said to plant more than one seed per cube because sometimes they wont sprout, one of my cubes has like 4 or 5 stems coming up because I put too many seeds, is this bad?

btw, the 9 cubes have been covered with a humidity dome and watered every day. They are also under a 15w black light, because I heard that the blue part of the light spectrum is best for growing, but not flowering.

What to do after sprouting?
I would give the plants another week or so. Don't let the stems get too long, especially if they are fragile. The plants may not survive. Some people "thin" the seedlings, basically getting rid of the ones they don't need or feel might not survive. I transplant them all. Your choice. I would get a four/five inch pot and fill it with good soil. Make two holes, one on opposite sides (with some space all around). It's best to transplant the seedlings when the soil is damp. Remove one of the set of plants from a cube. Gingerly tear the cube in half, or sections depending on how many seedlings you have. Try and keep some of the original soil from the humidity dome, it helps prevent shock when moving the plant to a new environment. Don't mess with the roots! Put the seedling in the pot and fill in the hole. Water the plants. Hopefully they will turn into full grown catnip plants.



Good luck!!!!!