They don't give you any time at all between each stage of the process so make sure you're not doing anything particularly important in the next few weeks. I was away on holiday when they invited me to do a video interview and my three days expired before I got back home. Thankfully they let me redo my interview when I told them about my circumstances.
The video application itself was horrible. Make sure you're really prepared. They flash up a question and you have 10 seconds to think of a reply. Then you have maybe 10-60 seconds to answer the question. It's very impersonal and it feels stupid to be talking to a camera about my experience in sales.
Remember where you applied. Once you've sent off the first application you can't view it again, so make sure you know what you've written down.