I have learn mostly by running an LND node myself. I don't know a lot of the technicals of how lightning works in code but I have learned how to operate a lightning node and setup channels.

What aspect of Lightning do you want to learn about?

1. Mastering the Lightning Network by Andreas M. Antonopoulos, Olaoluwa Osuntokun, Rene Pickhardt:

- This comprehensive guide covers the fundamentals and intricacies of the Lightning Network.

- https://www.amazon.com/Mastering-Lightning-Network-Andreas-Antonopoulos/dp/1492140493

2. Lightning Network Explained by Tim Ruffing, Pedro Moreno-Sanchez, Aniket Kate:

- A technical paper that explains the concepts and operations within the Lightning Network.

- https://eprint.iacr.org/2019/778

3. LN Book Open Source:

- An open-source book project on the Lightning Network by community contributors. It’s a continuously updated resource.

- https://github.com/lnbook/lnbook

4. The Bitcoin Lightning Network: Scalable Off-Chain Instant Payments by Joseph Poon, Thaddeus Dryja:

- The original whitepaper that introduced the Lightning Network, offering deep insights into its architecture and rationale.

- https://lightning.network/lightning-network-paper.pdf