I recently finished reading Learning jQuery 1.3 written by Jonathan Chaffer and Karl Swedberg, and while this version is merely a rewrite of an earlier edition, my review will be based on the book as a whole and will not compare differences. If you’re looking looking for that, try this review.
Anyone will find useful the list of resources and plugins at the end of the book. Something missing from the jQuery plugin repository is a way to filter through bad plugins to find the good ones. The list of recommended plugins in this book is a good place to start.
If you’re a jQuery beginner, I highly recommend this book. If not, you might want to pass it up for something more advanced. Here is a sample chapter on effects if you’d like to take a look