You can download Introduction to Electrodynamics 3rd Edition by David J. Griffiths free in pdf format.
About Book
The book deserves 5 stars just on the writing style and clarity of presentation. Professor Griffiths displays a mastery of the subject and makes a beautiful subject even more beautiful. Sure this is not a graduate level book but that does not demean it in any sense to Jackson – the two are aimed at different levels. I am a grad student and I still find this book invaluable. Professor Griffiths deserves an award for this work