Here is a short list of my favourite GIS blogs. Reading up-to-date blogs can help one advance their skills and learn new tips and tricks. I personally enjoy cartography blogs or technology blogs.
John Nelson [ArcGIS Blog] : For all the quick 1 minute map hacks & incredible ArcGIS Styles inspiration.
Heather Smith [ArcGIS Blog] : Love her art and cartography style. Also offers powerful GIS lessons.
James Fee [SpatiallyAdjusted Blog] : Super neat AI technology insights and augmented reality within GIS.
Bryan McIntosh [SpatialTimes] : Various topics including lots of Python and Javascript short reads.
Kurt Menke [BirdsEyeViewGIS Blog] : Unique cartography tips for QGIS users.
Take a peak, you won't regret it.