Todd Motto's angular style guide [1] has been one of the most helpful to me. It's always good to read multiple style guides and cherry-pick what works best for you :)
The recommendations in the module section are pretty awful - I'd avoid doing so, and every other expert in the community I've spoken to also disagree with that suggestion of using global functions wrapped in an IIFE to prevent it from being published on window, which seems to exclusively come out of Google.