One of my favorite websites as a Surface Pro fan. It's easy to find valuable tips and tricks on the Surface collection page. It contains essential, advanced troubleshooting tips, FAQs, and comparison sections. On top of that, it also has a neat spec sheet available for all Surface devices.
However, it doesn't cover all aspects of Surface tutorials. I would prefer them to cover more topics including installing Linux and Android OS, useful apps and games, and reviews.