Finding information targeting the latest Office 365 API builds can be a hard job, that’s why Chaks - PM at MSFT who’s currently owning the O365 API Tools - has summarized an awesome list with all important resources.

If you’re new to Office365 development and don’t know where to get started, I advice you to read at least this post

On top of that, he’s frequently blogging great articles on O365 and sharing examples on those APIs.