• debevec.org - The classic Debevec light probes
• HDRI Haven - Lots of high quality HDRIs for free, licensed under CC0
• aversis.be - Mirror ball photos in and around an apartment
• gl.ict.usc.edu - High-res stitched light probes
• hdri.3dweave.com - Low-res environment maps mostly from around Vienna
• HDRI Challenge - Background image and matching lightprobe

• 3dmodelfree.com - Hundreds of free models
• The Mesh Compendium - Many free models created or modified by the Caltech Multi-Res Modeling Group
• MGF Parser and Examples - Classic Radiance example scenes
• Hayabusa Project Science Data Archive - 25143 Itokawa asteroid model
• inTrace - Free green Beetle model, and more
• Large Geometric Models Archive - at Georgia Tech
• FastScan Samples - Hand-held laser scanner example models
• The Stanford 3D Scanning Repository - The classics
• The Digital Michelangelo Project - Need to apply for a license to download
• Image-based 3D Model Archive - models created for Carlos Hernández Esteban's Ph.D. thesis
• Powerplant Model - The 13M triangle powerplant model
• Official Blender Model Repository - Many free models in Blender format
• Sponza Atrium - The standard GI model in various formats
• Sibenik Cathedral - Another common GI model
• MIT CSAIL Textured Models Database - Scanned/textured models.

• Reflectance Data at Cornell - Fitted BRDFs for various paints, etc
• MERL BRDF Database - Wojciech Matusik's database of 100 measured materials
• Experimental Analysis of BRDF Models - High-res measured anisotropic BRDFs
• MERL/ETH Skin Reflectance Database - Fitted BRDF parameters for human skin
• BTF Database Bonn - Bidirectional texture function database
• CUReT - BDRF and BTF database

• Mayang's Free Texture Library - Hundreds of free high-res textures
• CGTextures - Even more free hig-res textures
• ImagerAfter Free Textures - Many textures, mostly photographic
• TextureKing - and some more
• Aversis - A few free textures

• Global Illumination Compendium - Great reference of formulas and equation in global illumination
• A Catalog of Radiation Heat Transfer Configuration Factors
• NeHe Productions - great OpenGL tutorials
• Ray Tracing News - Classic ray tracing newsletter
• John Burkardt's Homepage - Hundreds of useful graphics-related programs with source code!
• The Aggregate Magic Algorithms - Some useful bit-twiddling tricks
• stereopsis - Some neat graphics tid-bits
• Paul Bourke - Hundreds of graphics related articles with source code
• Eric Weisstein's World of Mathematics - "the web's most extensive mathematics resource."
• Geometric Tools - Extensive source code for the book "3D Game Engine Design: A Practical Approach to Real-Time Computer Graphics".
• Radiosity: A Programmer's Perspective - A full undergraduate-level textbook about radiosity (out of print) and now freely available as a pdf.

There are several search engines available which index graphics related papers.

• SIGGRAPH's Bibliography Database
• Citeseer - Scientific Literature Digital Library. Additionally includes paper abstracts, citations, bibtex entries, and links to pdfs.
• The Collection of Computer Science Bibliographies - Large database with bibtex entries for more than 2 million references.
• GraphicsPapers.com - Paul Nettle's reference database. Attempts to give links which are relevant to the paper (and may contain the paper itself).
• The ACM Portal - Full text of very article published by ACM. Also includes bibtex entries.

Several researchers have also made available specialized computer graphics related bibtex files which can be downloaded for off-line use.

• RADBIB and GITHESIS - Radiosity bibliography compiled by Ian Ashdown and Eric Haines.
• Ray Tracing Bibliography - Compiled by Eric Haines and Paul Heckbert (fairly dated).
• Computational Geometry Bibliographies - Maintained by Bill Jones, with over 8000 references.
• Paul Heckbert has made a few bibliographies available, including the bib file from the Graphics Gems IV book.
• Jim Arvo has made a few bibliographies available (over 2500 entries) for computer graphics, vision and related fields (check the software section).