The Journal of Light Construction (JLC) is aimed towards builders to provide information about the tools and techniques of doing the job right and profitably. Articles go into far more depth than This Old House (not that hard to do) with a focus on the specifications, performance characteristics and ease of use about particular materials or building technique... this real world orientation also extends towards how to be a profitable builder, while maintaining quality standards. I would imagine that this would be extremely useful to anyone in the building trades.
I am not a builder but find the magazine extremely useful and interesting. I have been fortunate to work with a number of fine builders on major rennovation and home building projects and the information from JLC has allowed me to better manage my projects and understand the building process.
I'd recommend the JLC to builders and others with a real interest and at least a moderate understanding of construction. Along with Fine Homebuilding, this is one of the more useful magazine titles on the topic.