It's hard to find the old-school texture art tutorials that would have been used in UT's time these days, so I've been scouring for everything I can get my hands on. This is a compilation of sites, PDFs, and videos, mostly using Photoshop.
The Identity Crisis and Skindom sites in particular have some great guides that are perfect for UT character texturing.
Sites Overview
-Barry Collins - Gives a broad overview of texture painting, modeling, and UV mapping.
-Game Art: Something for Everyone has a particularly good little section on skinning
-Ben Mathis - Contains a variety of guides on texture work
-BioRUST - Various Photoshop tutorials, with some more suited for web design
-Of interest might be the Metal, Wires & Cables, Rocks, and Wooden Planks
-BoBo the Seal - Mini tutorials on skinning and vertex baking
-BurstCC - Skinning guides for wood and metal (realistic guns in particular)
-CouchArtDotCom - Guides on creating metal with dodge and burn
-dyndns - Mostly guides on drawing and painting.
-The metal tutorial would be good for environments.
-GurusNetwork - Various photoshop guides.
-Photoshop guides mostly for web design, but some could be applied to texturing
-Curves, depth masks, the displace filter, metal, rocks, and more
-Hourences - A few photoshop/image editing guides from the man himself
-Identity Crisis - A lot of excellent texture art guides, including one (generally complete) series made with UT in mind
-Photoshop for Game Artists - Several quick guides on weapons, environments, and characters
-Lecture 5 breaks down texturing a weapon for Quake
-qbranch - Guides for cloth and metal textures
-Screaming Art Designs - 3d pipes, wires, chains, blood textures, and more
-Skindom - Some great step-by-step guides on skinning heads, metal, flesh, and clothing
-Wasted Youth - A nice selection of guides on shapes, metal, effects, and text (mostly image-complete)
-Misc - Assorted tutorials from sites that didn't get their own section
-Blood, character texturing, metal, stone
-The 3dtotal metal texture could have been made for Unreal
-Games - Quake, Graven, and Killing Floor
-flp's Quake site has a good skinning tutorial and example video
-The Killing Floor page covers metal and cloth skins
-Game Art: Something for Everyone has a particularly good little section on skinning
-Ben Mathis - Contains a variety of guides on texture work
-BioRUST - Various Photoshop tutorials, with some more suited for web design
-Of interest might be the Metal, Wires & Cables, Rocks, and Wooden Planks
-BoBo the Seal - Mini tutorials on skinning and vertex baking
-BurstCC - Skinning guides for wood and metal (realistic guns in particular)
-CouchArtDotCom - Guides on creating metal with dodge and burn
-dyndns - Mostly guides on drawing and painting.
-The metal tutorial would be good for environments.
-GurusNetwork - Various photoshop guides.
-Photoshop guides mostly for web design, but some could be applied to texturing
-Curves, depth masks, the displace filter, metal, rocks, and more
-Hourences - A few photoshop/image editing guides from the man himself
-Identity Crisis - A lot of excellent texture art guides, including one (generally complete) series made with UT in mind
-Photoshop for Game Artists - Several quick guides on weapons, environments, and characters
-Lecture 5 breaks down texturing a weapon for Quake
-qbranch - Guides for cloth and metal textures
-Screaming Art Designs - 3d pipes, wires, chains, blood textures, and more
-Skindom - Some great step-by-step guides on skinning heads, metal, flesh, and clothing
-Wasted Youth - A nice selection of guides on shapes, metal, effects, and text (mostly image-complete)
-Misc - Assorted tutorials from sites that didn't get their own section
-Blood, character texturing, metal, stone
-The 3dtotal metal texture could have been made for Unreal
-Games - Quake, Graven, and Killing Floor
-flp's Quake site has a good skinning tutorial and example video
-The Killing Floor page covers metal and cloth skins