This aims to be a comprehensive list of resources for all levels of engineers hoping to break into blockchain development.

1. Hello World contract - https://www.youtube.com/watch?v=nqw4FeYQBxc

2. Simple Crowdfunding contract - https://www.youtube.com/watch?v=UPmHjUTkxqs

3. ERC20 Token Demo - https://www.youtube.com/watch?v=3-h4OFc-aZk

4. Dependencies and importing contracts - https://www.youtube.com/watch?v=xtm1hOhaCjs

5. Using libraries - https://www.youtube.com/watch?v=M5v-H1oKBGU

Monax guides - https://monax.io/docs/solidity/

Smart contract best practices - https://github.com/ConsenSys/smart-contract-best-practices

Testing for throws in truffle Solidity tests - http://truffleframework.com/tutorials/testing-for-throws-in-solidity-tests

Hack this contract - http://hackthiscontract.io/

Ethernaut by Zeppelin - https://ethernaut.zeppelin.solutions/

Onward with Ethereum Smart Contract Security - https://blog.zeppelin.solutions/onward-with-ethereum-smart-contract-security-97a827e47702

Solidity anti-patterns: Fun with inheritance DAG abuse - https://pdaian.com/blog/solidity-anti-patterns-fun-with-inheritance-dag-abuse/

Lessons Learnt from the Underhanded Solidity Contest - https://medium.com/@chriseth/lessons-learnt-from-the-underhanded-solidity-contest-8388960e09b1

Blockstack reading list - https://github.com/blockstack/reading-list

Cryptoeconomics resources - https://github.com/snario/awesome-cryptoeconomics

Writing Upgradeable contracts in Solidity - https://blog.colony.io/writing-upgradeable-contracts-in-solidity-6743f0eecc88

Proxy Libraries in Solidity - https://blog.zeppelin.solutions/proxy-libraries-in-solidity-79fbe4b970fd

Library Driven Development in Solidity - https://blog.aragon.one/library-driven-development-in-solidity-2bebcaf88736

Upgradeable smart contracts - https://ethereum.stackexchange.com/questions/2404/upgradeable-smart-contracts/190#190

upgradeable.sol by Arachnid - https://gist.github.com/Arachnid/4ca9da48d51e23e5cfe0f0e14dd6318f

Solidity documentation - http://solidity.readthedocs.io/en/develop/index.html

Truffle documentation - http://truffleframework.com/docs/

Zeppelin documentation - http://zeppelin-solidity.readthedocs.io/en/latest/index.html

Ethereum Improvement Proposals - https://github.com/ethereum/EIPs/issues

ConsenSys Academy Resources - https://consensys.net/academy/resources/

Ethereum stack exchange - https://ethereum.stackexchange.com/

Ethereum Virtual Machine resources - https://github.com/pirapira/awesome-ethereum-virtual-machine

Cryptopals challenges - https://cryptopals.com/

Zastrin Course - https://www.zastrin.com