Art Tutorials
From The Battle for Wesnoth Wiki
The following a list of art tutorials compiled by the creators of wesnoth content, as well as links to other tutorials on the web.
Terrain Graphics
Terrain artist "Frame" has provided a tutorial describing the process of making terrain tiles in wesnoth, and how they interact with adjacent tiles.
Sprite Art
Once wesnoth's resident sprite slave, jetryl, gets a few things sorted out with this wiki, there will be several pages of interesting information linked here.
External Tutorials