This is a pretty valuable gardening resource. It's divided into manageable segments, month-by-month and general, trees/bushes, vegetables, and ornamental plants, along with a lot of numerical information at the end detailing soil types, pH, and fertilization charts.

For the most part I would ignore any advice from this book on when to sow seeds/harvest vegetables since it cannot pertain to every climate/zone out there. For that you should get more local information, such as a farmer's almanac. 

I did find a vast majority of the tips to be extremely helpful along with some tips I wouldn't have thought about before, such as building birdhouses, introducing ladybugs, or making a fishpond to kill potentially harmful insects. It also has great information on composting, building different garden structures, tool maintenance, and how to garden in greenhouses, rock gardens, and potted gardens.

The index is pretty detailed but it would be invaluable to have an electronic copy with a keyword search function. I think this is a gardening resource more for intermediate to experienced gardeners than it is for beginners.