Any time. Django has been improving their test suite recently, and their documentation on testing has been improving a lot in the last couple of months. There's also projects like Twill and Selenium for building automated tests that I like a lot.
Another thought on practicing deployment. If you really want to learn how to deploy to a multi-server environment, I'd move off of webfaction hosting and onto something like EC2. EC2 is great for being able to spin up and then spin down server instances at will. You could set up a DNS round robin pointing at 3 or 4 django servers which in turn point to a separate db server. Write the build scripts to automate set up and take down of all the separate servers. You could also practice setting up database replication on separate EC2 nodes if you wanted to. And, you're only paying a a couple of bucks a day to practice setting up multiple servers.
