Added some post-installation considerations

README.md

@@ -17,6 +17,15 @@ source bin/activate
 pip install -r requirements.txt
 ```
 
+Additionally, you should have an existing XMPP account for the bot to use.
+Ideally, the bot account and your recipient should be added to each other's roster and subscribed to each other's
+presence (although this might not be necessary in all cases).
+
+To verify the correct functionality, run the bot as instructed below and send any message from your recipient account
+to the bot. Errors about not being in the trusted device list are normal when you do this first, but should
+disappear upon sending any subsequent messages.
+
+
 ## Usage
 
 If you are using a virtualenv, make sure to activate it first by typing `source bin/activate` in this folder!