This morning one of my students asked me about how to work with UV texturing with Blender 2.5, since he is still using most of the time for an old project Blender 2.49. Is it much different? One of the simplest and direct tutorials about UV texturing for Blender 2.5 is the one made by pablolizardo. It shows pretty much the basics of the process, but it is just what is necessary for anyone with previous knowledge on Blender 2.49 to adapt their workflow to the new version of Blender.
For architectural visualization this is a technique that must be mastered before you dive into more complex and large scenes, otherwise you will have a lot of troubles during the render process, especially with external render engines.
Here is the tutorial:
Nice and easy tutorial.