Are you looking for technical papers on how they work or practical blog posts on what you can do with them?
For both Bitcoin and Etherium the original white papers do not paint a full picture of the state of each cryptocurrency. Here are a few links I recently read on both BTC and ETH:
Just read coindesk.com daily. Don't read tech forums like his one. Another ressource is the crypto tier from realvision.com. Then, look for YouTube channels or Podcast.
- Ethereum and others (Polkadot, Solana, Binance Chain) as the backbone of the new DeFi (decentralised finance)
What that means: DeFi is replacing Market Makers and the traditional finance space, lending and borrowing etc. So it's more used as financial tools for the backbone of the new financial industry.
There are obviously hundreds or thousands of projects trying to build on top of that, which I wouldn't pay too close attention to yet - or if you see it as a VC investment for 10+ years.
Information about these two are different. But coindesk.com is a solid resource, has many deep dives and daily articles about real world stories (like Visa using Ethereum for their crypto payment network etc.)
Then I would follow the links offered by coindesk, or look at the projects website themselves.
For the prospective developer or blockchain engineer the landscape is constantly shifting. I've found the Dapp University tutorials a great start. But it's best to just get an idea an implement it.
If you're looking for something more technical, the Week in Ethereum newsletter is incredible: https://weekinethereumnews.com
For learning the basics, the docs on the Ethereum foundation website will get you a long way: https://ethereum.org/