BTC-Tech: Bitcoin and Cryptocurrency Technologies from Princeton University - https://piazza.com/princeton/spring2015/btctech/home
The ethereum white paper starts with an excellent explanation of Bitcoin. https://github.com/ethereum/wiki/wiki/White-Paper
Start with https://en.wikipedia.org/wiki/Cypherpunk
If you aren't aware of their philosophy, the technologies won't really make that much sense to you because it is not strictly something technical. At its core it's a political movement.