selected the best seeds for germination, germinated and planted your germinated seeds, you now have plants in the seedling stage. This is the most crucial stage of your plants life. They are small and very fragile and are just starting to build a root system.
Since your seeds have just pushed themselves above ground and shed there jacket all they will need is a little light and water to help them grow. A CFL light will work great for seedlings and small vegging plants. They give off little heat and can be placed very close to the plant so it gets optimal lighting and won't stretch towards the light. Seedlings usually stretch when lights are to far away and have to much of a red spectrum. During the seedling and veg stage its best to use a light with mostly blue spectrum. So when using a CFL light for your seedlings look for ones that have a majority of blue spectrum. I believe cool white and soft white are the ones you want to look for.
Your seedlings wont need any nutrients. They will use the cotyledons (the embryo leaves) to provide it with the energy to grow a root system and the first set of true leaves. Once it has grown a root system the nutrients in your soil will be enough to feed it (adding nutrients could fry your seedling) So when you water your seedlings make sure its plain water that has an ideal ph range (that range should be 6.3 - 6.5 for soil). If your using tap water allow it to sit out for at least 48hrs to make sure any chlorine and other chemicals evaporate from the water. There are things you can add to the water you give to your seedlings but because this is growing 101 we will leave that for the Advanced Growing articles.
So all you really need to do for seedlings is provide the basics. Make sure the grow area is not too hott. A temperature of 78F while lights are on is ideal. You can also use a small fan on low to circulate your air and gently blow on your seedlings. Remember they are seedlings so you want the air to be very gentle but enough for it to move air around. This will strengthen your seedlings, also encouraging them to grow thicker stalks. As your seedlings move into the vegetation stage you can increase the speed of the fan to allow better airflow and give the plants a little more resistance to further strengthen the plant.
Once you notice steady growth and the roots start trying to grow out of the holes you know its time to transplant and get them ready for the vegetation stage and rapid growth.
Learn how to properly transplant your cannabis plant here