To know what your soil might need you need to have a good, reliable soil test done to see what is in your soil now and what might be needed and how much is needed before adding anything. contact your state university USDA Cooperative Extension Service about having this done. Often all you need do is add compost and other organic matter and your soil will reach optimal nutrient and pH levels.
Never, ever simply plunk some "plant food" onto your soil without that good, reliable soil test to guide you.

You can always add compost, you don't need a soil test for that.

Since you are going to have to buy whatever you add anyway, your best bet is purchased compost of decent quality until you can get your own production up and running.

Alternative organic additives if you have or can get them that can safely be added without a soil test would be shredded leaves, alfalfa pellets, (a mix of the leaves and alfalfa pellets is great stuff. It composts in place and my wife layers all her flower beds with them each fall.), composted manures, bone meal (good for the bulbs), and vermiculite.

But for best long term results it is hard to beat good compost. ;)

Dave

Compost, and any other organic matter, will over time add nutrients to your soil and that material is always a good addition. But anything else should only be guided by that good, reliable soil test because much of what you can add as a powder or liquid is water soluble enough that it could easily flow right out of your soil and pollute the ground water of many of us that rely on wells for that necessary stuff. Even municipal water systems have a hard time getting nitrates out of that water supply.

No, not a stupid question at all, but ... it needs focus to get the answers that you're looking for.

You know that the soil is important to gardening success, and that's a hugely important concept. Good for you to have figured that out so early!

But there's no way to know what your soil needs without more info. No you do not need a professional soil test, but you do need to know what kind of soil you have and its general drainage, water retention and nutrient status. You can figure all that out by yourself. You can get an over the counter soil test from the nursery that will test for general levels of nitrogen, phosphorus and potassium, and the pH. Unlikely you'll need more detail than that. You can figure out what kind of soil you have by putting some in a mason jar, filling the jar with water, shaking it up good and letting it settle. Sand settles out right away, silt takes a few minutes, clay takes a couple or three days. Organic matter floats on top or stays in suspension. Ideally you want about a 2:2:1 ratio of sand:silt:clay, or thereabouts. My own soil is about 80% sand, and no measurable clay, which is very annoying for gardening. Sand gives you drainage, clay and organic matter give you water and nutrient retention.

Compost is usually safe to add to any soil because it improves water and nutrient retention in sandy soils, and improves drainage in clay soils. Plus it adds basic food building blocks to the soil.

If you want to follow an organic program, go look at the ingredients of some organic fertilizers. You will find they contain ground up grains including soy, alfalfa, corn, wheat, and possibly some feather, blood, and bone meals. These ingredients provide real food for the microbes living in the soil. The feed includes protein, carbohydrates, vitamins, and minerals.

You don't have to spend the money to buy organic fertilizer. You can usually go to a feed store and get 50-pound bags of these materials for under $10 and often under $6. Use the same application rate as for the organic fertilizer (generally 10-20 pounds per 1,000 square feet), and give the fertilizer 3 full weeks to show improvement.

Like someone else said, I don't agree with the need of a soil test before adding organic fertilizer. It might be nice to know but the answer is always going to be "add compost and fertilizer." Lime is about the only thing that will differ.

Visit the Organic Forum and read all the FAQs for more info on organics.