Mastering Ethereum: Building Smart Contracts and DApps by Andreas M. Antonopoulos
How does Ethereum work, anyway? — how it functions at a technical level, without complex math by Preethi Kasireddy
Ethereum smart contract best practices by ConsenSys Diligence
Basic terminology for Ethereum — from gas to dapps (distributed apps) by Matt Condon
CryptoZombies is a free, interactive code school that teaches you to build games on Ethereum.
How to code your own cryptokitties style game on Ethereum by James Martin Duffy
The hitchhiker’s guide to smart contracts in Ethereum by Manuel Araoz