Useful stuff and books.

Hello everyone! Please share with me some good and useful stuff(literature, books, videos, blogs etc.) to fill my baggage of knowledge of “unmanned aerial system”. I want to start with basic topics and go deeper as i can step by step. I know that i can find all i need in google but i dont want to dive at chaos of information without preparation and basic knowledge. Please guide me experienced specialists. Thank you!

The Ardupilot wiki is BY FAR the most important thing to read

Then after that there are videos on YouTube, and posting questions on this forum.

What is it that you are interested in or that you’re trying to accomplish?