This is a 3-part podcast intro to the world of blockchain. It gives a broad introduction and doesn't assume any prior knowledge. Keep in mind that this was produced in Sept 2017, when the bull market was really heating up.
Hash Power - A Documentary on Blockchains & Cryptocurrencies
Bitcoin is the first blockchain and so much that has followed since has built off of concepts that were first introduced with Bitcoin. For this reason, it is important to deeply understand how Bitcoin works from a technical perspective. This video gives a great in-depth technical introduction to Bitcoin.
The Bitcoin Whitepaper was released on October 31, 2008 by 'Satoshi Nakamoto'. It is the original and canonical description of the Bitcoin protocol. It is definitely worth a read.
Ethereum was revolutionary because it first introduced the idea of a blockchain-based computing platform.
How does Ethereum work, anyway?
Below is a great illustrated guide to the Ethereum Virtual Machine. ([Original Link](Ethereum Virtual Machine Illustrated))