What do wordsmiths read? Here is a trio of recommendations from Grant Barrett, creator of the Double-Tongued Word Wrester's Dictionary and a lexicographer at the Oxford University Press:
Sidney Landau, Dictionaries: The Art and Craft of Lexicography
, second edition. There are several chapters of technical stuff a non-expert probably will just want to skim, but this is not an impersonal book. Landau is highly respected as a lexicographer of quality, so when he uses the word "I" in sentence in this book, it's a passage to pay close attention to.
Herbert C. Morton, The Story of Webster's Third: Philip Gove's Controversial Dictionary and its Critics
. The Webster's Third New International Dictionary was both highly lauded and highly loathed when it was released. More than 40 years later, it is still a topic of conversation. This book gives good insight into a common dictionary debate: whether they should tell people how to speak, or merely record how people actually do speak.
K.M. Elisabeth Murray, Caught in the Web of Words: James Murray and the Oxford English Dictionary
. The author is the granddaughter of one of the key editors of the OED, the man who made the dictionary what it is today.