Code examples from Go course about Go fundamentals
Go blog https://go.dev Great articles with clear explanation of concepts with examples
Go packages https://pkg.go.dev/ Documentation of Go packages with examples
Go by example https://gobyexample.com/
Articles
Composition with Go https://www.ardanlabs.com/blog/2015/09/composition-with-go.html
Testable Examples in Go https://go.dev/blog/examples
Advanced courses
Bill Kennedy Advanced Go Course - internals, performance, design https://www.ardanlabs.com/education/
Books
An Introduction to Programming in Go; 2012 by Caleb Doxsey; https://www.golang-book.com/books/intro
Videos