Elliptic Curves by Dale Husemoeller
First Edition sold over 2500 copies in the Americas; New Edition contains three new chapters and two new appendices
From the reviews of the second edition:
Husemoeller's text was and is the great first introduction to the world of elliptic curves ... and a good guide to the current research literature as well. ... this second edition builds on the original in several ways. ... it has certainly gained a good deal of topicality, appeal, power of inspiration, and educational value for a wider public. No doubt, this text will maintain its role as both a useful primer and a passionate invitation to the evergreen theory of elliptic curves and their applications (Werner Kleinert, Zentralblatt MATH, Vol. 1040, 2004)