[bootsz]

I recommend the Princeton course on Bitcoin and Cryptocurrency Technologies, available free on Coursera:

https://www.coursera.org/learn/cryptocurrency

I took this last year and found it very informative

[wdrw]

The Princeton bitcoin textbook is also excellent (see https://citp.princeton.edu/the-princeton-bitcoin-textbook-is... - it is easy to find PDFs online)

[john_jake]

I confirm, the course on Coursera is excellent!