This list is designed for a technology leader. I'm going to assume that the person who is looking at this is technical enough to know what a database is and roughly how the internet works, but will be less technical than other reading lists that are out there.

So, to begin, the first thing you need is a picture. Words are great and important and you can't understand distributed ledger or blockchain technology without words. But it is also important to have a picture in your mind, so you can refer to it later.

Here is the best picture I have found describing bitcoin specifically:

https://www.weforum.org/agenda/2016/06/blockchain-explained-simply/

Here is a good picture for distributed ledger more generally:

http://www.mbuguanjihia.com/tag/distributed-ledger

Here are some overviews, the first one is expressing the distinction between distributed ledger and blockchain:

http://finiculture.com/taxonomy-is-important-consensus-computer-is-the-end-game/

This is from IBM and introduces HyperLedger, which is a Linux Foundation Project they are supporting:

https://www.ibm.com/developerworks/cloud/library/cl-blockchain-basics-intro-bluemix-trs/

How do distributed ledgers fit into the broader world of data storage:

https://medium.com/@sbmeunier/blockchain-technology-a-very-special-kind-of-distributed-database-e63d00781118

A really good description of the problem distributed ledgers are solving:

https://bitsonblocks.net/2017/03/01/distributed-ledgers-confirm-as-you-go/

Do you need a distributed ledger?

https://medium.com/@sbmeunier/when-do-you-need-blockchain-decision-models-a5c40e7c9ba1

I hope this is helpful. I'm going to keep adding and editing. I may make it a static page at some point.