By far the most useful tool for DF texturing is Interkarma's Daggerfall Imaging, check out his blog for the latest version.
V2.0 download: http://www.dfworkshop.net/?wpdmact=process&did=MS5ob3RsaW5r
Blog: http://www.dfworkshop.net/Tutorials / Tips
Everything you really need to know is in the General Discussion topic, here's a quick list of things you should keep in mind:-Quadruple (4x) resolution.
-Realistically colored wood.
-Avoid obvious tiling
-Stored in .tga format with 128 transparency, higher transparency for glow effect
Browse through the forums and check out other member's textures to get some inspiration.Useful links
Our dropbox account: https://www.dropbox.com/home#/DXLTexPack:::3406423
(PM someone for an invite)
Paint.net, a great free image editor: http://www.getpaint.net/
This is so far really just rudimentary information. Feel free to post your own tutorials and tips in this thread, I'll try to keep this thread updated.