If you are looking for factual, straightforward, easy to read, scientifically honest information about organic gardening, you should get two books by Jeff Gillman entitled The Truth About Organic Gardening: Benefits, Drawbacks, and the Bottom Line 
Mr. Gillman combines his high level degrees in horticulture and entomology with a relish for gardening to present an even-handed, strongly research based evaluation of current gardening choices. His understanding of research method is apparent as he sifts through studies, past and present. If there is no significant data available, he has performed simple, but insightful tests of his own.
He clearly cares for the environment and the long term affects of gardening (or farming) techniques, but he cares about people, too. If an approach commonly accepted as ‘organic’ is also toxic or dangerous, he expounds on why and how to be careful. If a tactic is considered traditional, but has benefits, he elucidates that.
If his writing style is any indication, he would be fun to talk to in person. He is humble and entertaining. He is organized in his presentation. The books have been both great to read from beginning to end, as well as easy to use as a reference. I have found clear answers to questions that have bothered me for years. Skepticisms have been both verified and put to rest. Gardening, for me, has now lost some of the dark mystery and I will be able to proceed more economically and with more complete delight.
The Truth About Organic Gardening
The Truth About Garden Remedies
