The Miniatures and Terrain Blog has this tutorial on modeling wooden road obstacles.
Modeling
Modeling Wood Stacks
Here’s a photo tutorial on making some nice looking model wood stacks. Useful stuff for battlefields across the centuries.
Making A Medieval Town Building
Here’s a nice photo essay on making a medieval town building.
Scratchbuilding Corrugated Roofing
Corrugated metal roofs are a ubiquitous feature in third world and post-apocalypse game settings. Here’s a nice tutorial on creating them.