In the "wine-drinking" countries (which excludes the US, by about a
factor of 10 per capita), a knowledge of wine at the casual level is
pretty widespread. When people want to know more, they turn to
an expert. This is typically someone who has spent his or her life
in some part of the wine trade and therefore whose livelihood has
depended on ability to satisfy, and accurately advise, customers.
There are even highly respected standards such as the British
Master of Wine examination that will establish whether a person
genuinely knows the subject and can also smell and taste all of the
nuances that he claims to. (The MW exam is notoriously revealing
and would undoubtedly depopulate overnight the ranks of the
self-appointed US wine pundits, which may be why many of them
pointedly avoid reference to it.) In the US, which lacks most of
these traditions, any musician or sportswriter or lawyer can claim
to be a wine expert and there's a fair chance they'd get a Following,
self-perpetuating on the basis of popularity.
Fortunately in the US, relying on such writers is not (yet) compulsory.
It is possible to get books by English-language writers of very high
caliber and experience, who mostly are in other countries (such as
Clive Coates, Serena Sutcliffe, Remington Norman, and Michael
Broadbent). Stevenson comes from this tradition, and although his
book is not as specialized as those of the other authors I've just
named, it is compensatingly broad. There is a desperate need for
accessible one-volume introductory wine books. Blake Ozias's "All
About Wine" served this need in the US, 25 or 35 years ago, but it
is badly out of date (not to mention out of print); it was a thin book
you could absorb in a few evenings. Stevenson's is different, it is
a genuine encyclopedia, combining succinct overviews of all kinds
of wine-making regions (including Texas and Mexico) with further
depth on producers and labels in the larger regions. The compact
snapshot on Beaujolais, for example, is superb, first laying out the
history and styles, then illustrating many producers that you will in
fact encounter in the shops. It distinguishes the deep, complex
wines that the region can make from the bubble-gum style that has
become more common recently. More generally, if you found a
random bottle of wine that you were interested in, there is a decent
chance you could look it up in Stevenson and learn much more.
This is the best single-volume general wine reference I'm currently
aware of. I have recommended it to several people who wanted to
learn more about wine and all of them have been very satisfied.