This post is more like a personal note of the resources indicated by Balaji as a must read if you want to start the journey of understanding crypto currencies and the underlying technology.
Mastering Bitcoin is a book for developers, although the first two chapters cover bitcoin at a level that is also approachable to non-programmers. Anyone with a basic understanding of technology can read the first two chapters to get a great understanding of bitcoin.https://github.com/bitcoinbook/bitcoinbook
Mastering Ethereum is a book for developers, offering a guide to the operation and use of the Ethereum, Ethereum Classic, RootStock (RSK) and other compatible EVM-based open blockchains.https://github.com/ethereumbook/ethereumbook
Andreessen Horowitz list of crypto related resources.
The course videos from a16z’s Crypto Startup School, held in the spring of 2020.
CryptoZombies is an interactive school that teaches you all things technical about blockchains. Learn to make smart contracts in Solidity or Libra by making your own crypto-collectibles game.https://cryptozombies.io/