Very detailed blog series giving an introduction to all parts of Unreal Engine, very good for beginners
Very good overall tutorial about how to create a shooter game with many more additional information
Very good tutorial about how to build a RTS
Gigantic tutorial about how to build a RTS (yes, 2 days of Youtube video)
Very good tutorial of all basics with very recent version in usage.
Set of open-source lectures, assignments and project files offered free of charge that guides students from creating simple materials and Blueprints in the Editor all the way to implementing their own shader code directly into the engine using C++ and HLSL.
Kitatus exists to help you gain a better understanding of Unreal Engine 4’s features and helps you take your projects to the next level
Very good starter example set for understanding the basic functionalities of the Engine
Star Wars themed sample project described in this Article. Other Mirrors: Mirror 1 Mirror 2