Here’s a helpful video that shows how you can optimize your Canon DSLR for video recording based on Vincent LaForet‘s recommendations. It’s geared towards the 5D Mark II, but is applicable for other video-capable DSLRs as well (e.g. 5D Mark III and 7D). There’s also an article over on LaForet’s blog that explains the reasoning behind the various settings.
Setting up your Canon 5D MKII [Vincent LaForet]