That's very true about improving the soil. Your local Cooperative Extension Service office can give you some good basic information, and can recommend a lab that could so a soil test for you. Most basic tests cost around $10.

There is a video called "Hands-On Agronomy" that could be a valuable source of basic soil information for about 90 minutes of your time.

Most soils have some deficiencies, and some have a lot. It's best to deal with them while the ingredients are still available.

U.S. Cooperative Extension Offices: http://www.csrees.usda.gov/Extension/

Sue