Hi Jonathan --
That Coursera course (Bitcoin and Cryptocurrency Technologies) is actually very good, taught by Princeton faculty, and easy to follow along. It provides a good foundation on cryptography and walks you through the basics of how a blockchain is created, all the way up from the genesis block. Don't feel intimidated by the coding exercises - if they're beyond your expertise, skip through them and you'll still gain a lot from the course lectures.
It isn't a course, but this is the best "introduction to Ethereum" explanation video I've seen so far - makes sense that it was done by Vitalik Buterin, founder of Ethereum. This video really exposes the backend/technical fundamentals of Ethereum.
I strongly recommend investing in cryptocurrencies as a means to learn how blockchain technologies work. Beyond simply buying/selling currency, as a means to learn blockchain, moving small amounts of money around your various wallets is a great way to track transaction times and watch how blocks are related to each other through a tool like Etherscan. I describe this in a bit more detail on a LinkedIn Article I published recently.
Another bit of "learning by doing" is to build your own private blockchain on Ethereum. This Consensys tutorial was simple to follow.
There are lots of blockchain courses hanging out on the web, like this one on Udemy which is only $10 - so not much to lose. But as I continue my learning journey I'm realizing the benefits of diving into a specific language like Solidity - which is the Ethereum Virtual Machine programming language. This platform-specific learning approach seems to lend itself to quicker real-world application, i.e. developing a product.