So it's finally time to start your seeds. Now what? Moisten your seed starting mix and fill your pots or cell packs. Check the instructions on your seed packets for planting depths and other useful information. For example, some seeds require light to germinate and should not be covered with seed starting mix. Most seeds, however, should be buried in the mix.
When you are ready to plant the seeds, double-check the planting depth and slip a couple seeds into each pot (the weaker seedling can be snipped off later). Make sure to label your pots (it might be a couple weeks before the seedlings start to resemble something familiar and you don't want to forget what's what). Using permanent marker, tag each pot with the crop's name and sowing date. Cheap tags can be made from strips of milk jug and stuck into the soil. I do not recommend using popsicle sticks as they can get moldy and the writing will bleed and become illegible.
Cover the newly seeded pots with plastic (a humidity dome, saran wrap, or plastic bag) to keep the humidity high and put them under your lights. If you have an electric seedling heat mat, plug it in and put your pots on top. Check your pots frequently. Mist with water if you stop seeing condensation on the inside of your plastic and water lightly if the soil starts to dry. As soon as you see any green bits popping up from the soil, take the plastic off. At this point, the seedlings fresh air and the highest light levels possible. If you keep them in the humidity dome too long, disease (such as damping off) can become a problem. Continue watering regularly and in a matter of weeks, the seedlings will be ready to transplant into the garden!