I know you said “self hosted”, but if you are interested in an Android app, Google Play Books does most of what you want, I think. You can upload your books, and read them on any device (with offline capabilities). But this is the Self Hosted community, so I will show myself out.

I would add Ars Technica to that list and call it a day.

For programming I follow YouTube channels of the conferences relevant for my tech stack (YouTube natively supports RSS). They are generally 1 hour talks but it’s a great way to stay up to date.