Bash can't find go exectuable after installing Go package for OS X
Go should be installed to either /usr/local/go/bin or ~/Go/bin — I can't test the installer now.
Try editing your ~/.bash_profile by calling:
nano ~/.bash_profile
Then adding:
export PATH=$PATH:/usr/local/go/bin
Save the file by pressing CtrlO, then ↩, and reload your shell (e.g. by restarting the Terminal). Now, go should work as a command, assuming it is provided as /usr/local/go/bin/go.