About a year and a half ago, Darren Glass wrote a glowing review of the second edition of Volume 1 of Enumerative Combinatorics. Both volumes already had pages on MAA Reviews, because both appeared in the MAA's Basic Library List with the strongest possible recommendation: "The Basic Library List Committee considers this book essential for undergraduate mathematics libraries." At the time, I put off doing a review of the second volume because I assumed that it too would receive a second edition. This must have been a common assumption, because one now finds a note on Stanley's web site indicating that "there will be no second edition of Volume 2." The point is that Volume 1, originally published in 1986, needed spiffing up, while Volume 2, born in 1999, does not.
Given that, let me just point you to our review of volume 1 and add only that this is the real thing, a book universally considered the gold standard in its field. Anyone interested in combinatorics is going to need to have both volumes on their shelves.
Fernando Q. Gouvêa is the editor of MAA Reviews.