Ideally you should put about two inches of mulch over the area where the root ball is planted. However, be careful that the mulch is not up against the bark of the trunk, as this may cause the trunk to rot. If your soil is not acidic you need to lower its' pH. There are lots of inexpensive, organic ways of doing this. For example, place ground-up citrus rinds on the top of the soil. However, I also recommend a commercial fertilizer called Hollytone made by a company called Espoma.
All pine trees prefer full sun light.
However, they will live in partial shade. If you plant your pine tree in partial shade though it will grow at a snails pace. Pines do not need an excessive amount of water. They are average in this regard. What holds true for them is true for almost all plants.