|My seeds are up in my greenhouse and now I need some help with what to do next, as far as fertilization, etc.
|Keep a close eye on watering, making sure the seedlings' soil never dries out completely. On the other hand, don't keep the soil soggy either. As your seedlings grow and the roots begin to fill the pots, if you are not ready to plant them outdoors you'll want to transplant them to larger pots.
I like to fertilize my seedlings about twice a week, as long as they are actively growing and looking healthy. I use a very dilute complete fertilizer (like Miracle-Gro 15-30-15), mixed at 1/4 to 1/2 the recommended strength. This gives the seedlings an almost constant supply of nutrients.