This is a fantasic book. So full of information and advice.
Simple things such as the use of test strips and contact sheets are explained properly, definitely a "don't leave home without" technique to better pictures.
More complicated techniques are also suberbly dealt with - using bleaches to alter highlights for instance. Even the chemicals themseleves are explained and the mixing instructions.
The giant f-stop printing chart is excellent as are the other reference lists.
Don't expect to read this book from cover-to-cover. Its a reference book. Have problem, look it up in here and see how to improve things.
A must for anyone who, like me, spends hours in their darkroom trying to get 'the one print' that makes it worthwhile!