Go hasn't changed much such its first public release. The blog is good.
Go has compatibility guarantees.
Go 1 and the Future of Go Programs
Introduction
Expectations
Sub-repositories
Operating systems
Tools
Introduction
The release of Go version 1 (March 2012), Go 1 for short, is a major milestone in
the development of the language. Go 1 is a stable platform for the
growth of programs and projects written in Go.
Go 1 defines two things: first, the specification of the language; and
second, the specification of a set of core APIs, the "standard
packages" of the Go library. The Go 1 release includes their
implementation in the form of two compiler suites (gc and gccgo), and
the core libraries themselves.
It is intended that programs written to the Go 1 specification will
continue to compile and run correctly, unchanged, over the lifetime of
that specification. At some indefinite point, a Go 2 specification may
arise, but until that time, Go programs that work today should
continue to work even as future "point" releases of Go 1 arise (Go
1.1, Go 1.2, etc.).
Compatibility is at the source level. Binary compatibility for
compiled packages is not guaranteed between releases. After a point
release, Go source will need to be recompiled to link against the new
release.
The APIs may grow, acquiring new packages and features, but not in a
way that breaks existing Go 1 code.