Migrating your Django Project to Heroku is a full tutorial on using Heroku to run Django web applications. It includes instructions on converting from MySQL to PostgreSQL if necessary as well as how to properly handle your settings files.
Heroku's official Python documentation is fantastic and walks through deploying WSGI applications in short order.
Production Django Deployments on Heroku aims to simplify the process of deploying, maintaining, and scaling production-grade Django apps on Heroku.
Deploying Django to Heroku With Docker looks at how to deploy a Django app to Heroku with Docker via the Heroku Container Runtime.