Any potential gotchas or things to be aware of for a newcomer to Django?
Use forms for all data validation.  Bulk loading, batch processing, web services, everything.  
At first, it seems odd to read a CSV file, populate a Form, and then have the Form validate the data and build the database object.  But that's the way it's supposed to work.  Use the Forms for all validation no matter what the data source.
In other words, what did you not know when you started with Django that you wish someone had told you?
I've dabbled some in Django but nothing really serious. However, I'm hoping to change that, and I'm wondering if there's any gotchas/shortcomings/whatever that I need to be aware of as I  go.