Here are a few articles you might consider:
http://uccemg.com/Soils-Fertilizers-Compost/
The following will discuss how to test your soil, how to manage your soil, and adding soil amendments;
This link will give a few places to purchase soil amendments:
http://uccemg.com/Soils-Fertilizers-Compost/Soil_Amendments/
Please visit the many topics discussed and helpful information you will discover on the above mentioned website pertaining to your landscape needs.
Remember the old adage, always put a $1 plant in a $5 hole!