According to Gardening for Dummies, my instructors at the pruning and soil class I attended Thursday night, and www.thegardenshed.net, a good first step when planting a garden is taking a soil sample and having it professionally analyzed.
Many gardeners fight year after year with problem spots and plants in their garden. They try different nutrients, additives, and techniques hoping to get their garden to grow. A good way to avoid this frustration is to send your soil away for analysis. A professional analysis, like the one I've sent away for from Waters Agricultural Laboratory, will cost you less than $20 and provide you with specific information on what your garden needs more or less of. Save yourself the insanity of years of failing plants!
The truth is that all regions are different so my garden in central Maryland may need quite different additives than your garden.

- Dig a small hole down 4" - 6". Make sure to use a clean and dry shovel
- Scrape out about 1 - 2 cups of soil and put them in a zip lock bag. Be sure to remove any extraneous stuff (leaves, worms, grass, etc). If you want, you can take samples from different places in your yard and mix them together. Or, if you're going to do different things (vegetable garden vs. lawn) in different areas of your yard, you may want to get one test for each functional area.
- Pick out a soil testing laboratory (see the last page of this pub) and mail your sample, along with their order form, to it.