James Busby demonstrates nondestructive image flattening and reflection removal in Photoshop.
Free Photoshop Brushes
Several professional artists have made available their Photoshop brushes for free.
Making of Villa Bonafe - Living Room
Evermotion present a modeling and post production tutorial by ADC Visualizations on the making of their Villa Bonafe image.
Gnomon - Design Techniques for 3D Concept Art
The Gnomon Workshop present Design Techniques for 3D Concept Art, a DVD tutorial by Gavriil Klimov.