Video, recorder question!! ?

Im going to record a video of myself and post it on youtube. But i want my video to be clear, HQ, the sound is good (will i be needing a mic?, what if i dont have it is there any way to improe it?) can u give me a name of a site where i can improve or edit a video? Can u give me some tips? So the people will like my video? This is my first time and im actually goingbto cover a song as for my audiion video.. Thank's!! :))))