Ok, first, you need a video editor to edit everything (for Windows, I recommend Windows Movie Maker), whether you want to make a music video or just point the camera at you while you're singing it. Next, you need an Ipod or any other music playing device, like an MP3 player or smart phone that has the song you want to sing, then put on some headphones and plug them into the device that has the song. That will help you sing with the music to make sure you don't go ahead or behind the song. Now you need a decent camcorder or smartphone to record the video. 720p is the minimum to record with, if it is not HD, most people won't listen to your cover. But full HD, 1080p is recommended. A good singing voice is also needed! Now, you can use the camera's microphone or get a better quality one.
Once you have all that, lets begin...
Step 1: Step 1
Take the camera and point it at you, put on the headphones and start the song. Start MOUTHING the words that you want to sing, don't actually sing it.