> I recommend this blog post: https://nick.groenen.me/posts/rust-error-handling/

This blog post is good indeed. The discussion on /r/rust linked at the end of the post is also worth reading.

Another good and light introduction is http://www.sheshbabu.com/posts/rust-error-handling/

And a more in-depth look https://blog.burntsushi.net/rust-error-handling/