I recently joined the organic gardening Yahoo group and one of the first posts highly recommended Teaming with Microbes.

I just finished the book this morning and it is truly FASCINATING stuff.
I've been seeing references to fungi, inoculation and compost teas and that it improves root and plant growth, but I had no idea why and how it works.
And while I knew that chemical fertilizers and pesticides are bad for us and the soil, I didn't understand the extent of the damage, what soil is and how plants “eat”.
Now I appreciate more than ever the fact that we live on “virgin land” — as unpolluted as it gets, since it was undisturbed desert when I bought it in 2006.  I switched to organics when I moved.
The first part of Teaming with Microbes covers the SCIENCE and Jeff Lowenfels & Wayne Lewis did an excellent job explaining how bacteria, archaea, fungi, algae and slime molds, protozoa, nematodes, arthropods, earthworms, gastropods and reptiles, mammals and birds work together and live in symbiotic relationships with each other and plants.
My school didn't have any microscopes and I don't remember learning about all those tiny organisms, so this was mostly news to me.
The second part of Teaming with Microbes is about practical applications and while I could have skipped the chapter on lawns, I found it interesting too.  Our dogs would love some grass to roll on.
The bottom line: don't till and don't turn over the soil as it disturbs the soil and its many inhabitants.
Instead of doing all that hard work, you simply apply compost, compost tea and/or add fungi as needed.
I also learned that the BROWN mulch we just put on the veggie beds should have been mixed into the soil (as we did before we planted) and that veggies should be mulched with (formerly) green materials.  Of course we don't have grass clippings (in the desert), but we recently bought some rabbit food (alfalfa, w/o antibiotics) and we have some old rotting straw.  That's as good as it gets around here.
An online PRIMER for soil biology is at http://soils.usda.gov/sql/concepts/soil_biology/biology.html
I'm very excited and we're going to try to brew some compost tea right now.
This is not traditional compost / manure tea, but AERATED tea and completely different:
Compost Tea – as easy as 1, 2, 3

We don't have an electric air pump yet, but we just modified a hand pump originally designed to blow up air matresses and we're giving it a try.
We have only very little worm  poop as I've been adding worms and castings to the pots when I recently transplanted. So we supplement with brown mulch and some rabbit pellets and we have unsulphered molasses.
This sure is exciting!