Have a look at these resources:
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1. A Tour of Go: https://tour.golang.org/welcome/1
>> A nice step by step introductory guide through the language.
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2. Go by Example: https://gobyexample.com/
>> A concise collection of fundamental concepts, expressions, and implementations.
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3. The Go Programming Language: http://www.gopl.io/
>> The text by two authors of the language. You may view as the "KnR" for C but for Go.
>> It has end of chapter problems and the solutions are hosted on github:
>>> https://github.com/adonovan/gopl.io/
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4. Effective Go: https://golang.org/doc/effective_go.html
>> Advice on writing solid Go.
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5. Official Go Page of Documentation and Other Resources: https://golang.org/doc/
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6. The Go Language Specification: https://golang.org/ref/spec
I haven't watched the videos yet but the site looks really simple and attractive.