Tangent Space Normal Mapping
Sep, 2006 - Jonathan Kreuzer
Pretty simple article that explains the basics on tangent space normal mapping. It assumes some previous knowledge on the subject.
Object Space Normal Mapping with Skeletal Animation Tutorial
March, 2006 - Jonathan Kreuzer
This article explains object space normal mapping, and also shows how to use it together with skeletal animation.
Real-Time Caustics Rendering
StarCraft II - Effects and Techniques
2008 - Dominic Filion, Rob McNaughton
This article describes how Blizzard have solved their needs for the graphics engine. It covers areas such as Deferred Rendering, Deferred Lighting, SSAO, Depth of Field, and Translucent shadows.
Inigo Quilez - fractals, computer graphics, mathematics, demoscene and more
Interesting articles on various areas, as mentioned in the title. Especially valuable for those who are interested in procedurally generated content.