Resources for HoloLens Development
The Microsoft HoloLens is a mixed reality headset that allows the user to interact with digital "holograms" that are rendered over the physical environment. These objects can be interacted with through gesture and voice input and are build with the same libraries that power the Windows Mixed Reality family of devices. There are a growing number of resources online for learning HoloLens and Windows Holographic development.
Microsoft has an extensive set of tools available for learning about and building for HoloLens. You can follow the tutorials online at the Microsoft Holographic Academy to learn about the different input options and common functions that the HoloLens supports, and to get familiar with spatial mixed reality computing. Unlike virtual reality platforms, with HoloLens and other mixed reality headsets, you have to consider spatial mapping and how your digital objects blend in with the physical world around a user.
Keep an eye out for HoloLens events in your area at HoloLensEvents.com
Getting Started
You can get started developing for HoloLens without a device. The emulator for developing on HoloLens can be used with the Unity game engine, which has support for the entire Windows Mixed Reality platform, including HoloLens, built-in.
If you are familiar with the Unity game engine, go ahead and dive right in to the Microsoft Holographic Academy coursework to get you started:
Setting up your Environment for Building with HoloLens
If you're new to Unity, take a look at the documentation on the Unity website about Mixed Reality development to get an overview of the basics:
Unity XR Development Resources
If you have experience with Unity and are familiar with the building blocks of virtual / mixed reality development, you may prefer to jump into the more advanced Microsoft Holographic Academy tutorials, or to go directly to the source code of one of the sample applications, which are up on GitHub:
Galaxy Explorer
Periodic Table of the Elements
Lunar Module