diff --git a/README.md b/README.md
index d52e982..a4d803f 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,13 @@ To install all pending updates run `mas upgrade`.
     ==> Downloading iFlicks
     ==> Installed iFlicks    
 
+To sign into the Mac App Store for the first time run `mas signin`.
+
+    $ mas signin mas@example.com "ZdkM4f$gzF;gX3ABXNLf8KcCt.x.np"
+    ==> Signing in to Apple ID: mas@example.com
+
+Use `mas signout` to sign out from the Mac App Store.
+
 ## Build from source
 
 `mas` currently requires the [bundler](http://bundler.io/) RubyGem in order to