Eager to get started on YouTube? Shure has launched the MoveMic wireless microphone system for smartphones, which could be what you need. We've reviewed it.
You can create professional-looking videos with just a smartphone, but the audio is trickier to get right. If you’re going to create YouTube videos or other content, the Joby Wavo Air wireless microphone system is a great item to get you started, as long as it fits with what you plan to create.