Prof. Gilbert Strang
Published in 1991 by Wellesley-Cambridge Press, the book is a useful resource for educators and self-learners alike. It is well organized, covers single variable and multivariable calculus in depth, and is rich with applications.
In addition to the Textbook, there is also an online Instructor's Manual and a student Study Guide. Prof. Strang has also developed a related series of videos, Highlights of Calculus, on the basic ideas of calculus.
The 2010 second edition of the Calculus textbook includes a new chapter on "Highlights of Calculus" that connects to the video series of the same name. The new chapter has summaries and practice questions for all of the videos. It also introduces The Exponential Function (e^x) as presented in Prof. Strang's video on this topic.
Strang, Gilbert. RES.18-001 Calculus Online Textbook, Spring 2005. (MIT OpenCourseWare: Massachusetts Institute of Technology), http://ocw.mit.edu/resources/res-18-001-calculus-online-textbook-spring-2005 (Accessed). License: Creative Commons BY-NC-SA