What are some general UX best practices when notifying the user that something in your app has changed?
There are two ways of doing it.
Force to action. Redirect user straight to the information you want to to read. Examples: Google, PayPal, Barclays Bank terms and conditions.
Call to action. Throw a little message at the top of the page or even on the top of the header inviting users to read "what's new".
Your practice should depend on the situation you are in. Google, PayPal and my bank can tho something like that because no matter what they wrote there I want to get to my emails, money, ability to pay bills quickly. People like myself agree to new term without reading.