Nim by Example[0] is a great introduction. The blog mentioned in the OP also has a writeup that explores some of the tooling[1]. After that, the official tutorial[2] is a comprehensive dive. The standard library documentation is sometimes lacking but is easily searchable.

[0]: https://nim-by-example.github.io

[1]: http://howistart.org/posts/nim/1/

[2]: https://nim-lang.org/docs/tut1.html