There is a lot of material on relativity on the Web, not all of it reliable! Here are my favourite links:
Relativity
FAQ
(from the usenet newsgroup sci.physics.relativity)
Mathematical
History of Special Relativity
(on the St Andrews maths archive)
Einstein
(from the AIP history project)
Dave's
Relativity Page
(introduction - Dave Slaven, Morningside
College)
The
Light Cone
(java animations - Rob Salgado, Syracuse University)
Special
Relativity
(movies and more - Andrew Hamilton, Colorado
University)
Lecture 1
Lecture 2
Lecture 3
Lecture 4
Lecture 5
Lecture 6
Lecture 7
Lecture 8
Feel free to email me
if you have a specific question concerning my lectures
(but do attempt the problems yourself!)