Special Relativity at Colorado University 
This site offers a very detailed explanation of special relativity, with emphasis on paradoxes and generally accepted theories.

How Do You Add Velocities in Special Relativity?
Here is the formula for adding velocities in special relativity when motion occurs in a single direction.

Special Relativity Lecture Notes  
A standard introduction to special relativity where explanations are based on pictures called spacetime diagrams.

An Intuitive Derivation of the Lorentz Transformation  
A derivation of the fundamental equations of special relativity without using the constancy of light postulate.

Relativity Tutorial  
An introduction to relativity using space-time diagrams.

Special Relativity  
A brief overview of the theory of special relativity, and how it pertains to particles at SLAC (Stanford Linear Accelerator).

Relativity in its Historical Context  
The discovery of special relativity was inevitable, given the momentous discoveries that preceded it.

Relativistic Contraction 
Those who teach special relativity consider it a very important exercise to have students decide how to measure the length of a rapidly moving object.