This book was first recommended to me during my second year, in the Animated short film class. As soon as I started reading it, I regretted not reading it before making my first student film. Even though McKee concentrates on feature screenplays, he gave me fundamental ideas on how to approach story on a smaller scale as well.
I liked how the book teaches storytellers to focus on the audiences' emotional experience of their work, rather than on their own self-expression.
McKee is a Hollywood writer so don't expect much avantguard here - this is about proven filmmaking conventions, not experimental ones. Maybe that is why McKee should be read as a reference, not as a bible.
It's a nice comprehensive roadmap to have before starting (it really motivates you when you get started) and then again when you get stuck, or when it's done and something doesn't feel right.
Enjoy!

Alex