Usability News is a free web newsletter that is produced by the Software Usability Research Laboratory (SURL) at Wichita State University. The SURL team specializes in software/website user interface design, usability testing, and research in human-computer interaction.
It's obviously pretty academic, but there is tons of great material in the papers they produce. I've found their archive of articles to be really useful when looking for research and evidence to inform the starting point for design recommendations.
Usability News archive - usability articles from Wichita State University