If you are new to .NET, or not, you should check out the new YouTube channel. There are lots of channels like Microsoft Developer, Xamarin Developers, .NET Foundation, Visual Studio, Azure DevOps, Microsoft Mechanics, and more.
Check out the video from Channel 9 to get a few really useful tips to debug your code in .NET and C++. https://channel9.msdn.com/Shows/Visual-Studio-Toolbox/Debugging-Tips-and-Tricks-Part-1
Here is a great article on unit testing coverage written by my fellow Microsoft MVP Jeremy Clark. Microsoft actually told me that a good coverage goal should be 75%. https://jeremybytes.blogspot.com/2016/08/code-coverage-should-not-be-goal.html
Here is a great video that show Visual Studio editing features that you might not know about. https://channel9.msdn.com/Shows/Visual-Studio-Toolbox/Developer-Productivity-in-VS-2015-and-VS-15/player?format=flash
Here is a great, quick video on how to create a simple Universal Windows App: https://mva.microsoft.com/en-us/training-courses/quick-start-challenge-universal-windows-apps-in-visual-studio-14477?l=Be2FMfgmB_505192797
Here is a great video from Channel 9 that discusses how development can still be hard. I totally agree... many aspects of development are harder than they use to be. As an architect it's a daunting task to come up with a lasting solution. Click here to view the video.
Here is a great video on some of the new code analysis built into 2015! https://channel9.msdn.com/Shows/Visual-Studio-Toolbox/Fixing-Coding-Mistakes-On-The-Fly-in-Visual-Studio-2015/player?format=smooth
Here is a good video demonstrating a few of the cool new debugging features in Visual Studio 2015. https://channel9.msdn.com/Events/Visual-Studio/Visual-Studio-2015-Final-Release-Event/Universal-Windows-Apps-Debugging-and-Profiling/player?format=html5
Here is a great video on one of the new features in EF7. https://channel9.msdn.com/Blogs/Seth-Juarez/Key-Generation-Strategies-in-Entity-Framework-7/player
Check out this video from Channel 9 about what is coming in the new release in VB.NET 14. Click here to view.