update

README.md

@@ -1,4 +1,45 @@
 learninggo
 ==========
 
-a playground to learn golang
+### Setup go developing environment
+
+#### install golang 
+
+[download from here](https://golang.org/dl/)
+
+#### setup GOPATH and GOROOT env
+
+```
+export GOPATH=$HOME/code/go
+export PATH=$GOPATH/bin:$PATH
+```
+
+`$GOPATH` is where you put all of your go code
+
+
+#### initialize gopath
+
+```
+mkdir -p $GOPATH/{bin,pkg,src}
+```
+
+congratulation, you are good to go
+
+#### run your hello world
+
+```
+mkdir -p $GOPATH/src/hellogo
+
+cat > $GOPATH/src/hellogo/main.go <<EOF
+package main
+
+import "fmt"
+
+func main() {
+  fmt.Println("hello world")
+}
+
+EOF
+``
+
+go run $GOPATH/src/hellogo/main.go