To me, nowadays, the hardest part of learning a new technology or language is not the “thing” itself but the environment around it.

Make content about environments.

Example: I want to start doing Ruby. There are probably 49 ways to setup a decent working environment and hundreds of people putting a lot of tools together to get it started. They all conflict with each other and almost none are clear. Any material that can explain environments in a way that make sense and help you get started as efficient and completely as possible is gold.

This is true for all platforms today.