That's hard to answer easybeat. I am pretty slow when it comes to learning new songs. And as you notice I do have mistakes in them, but I tend to be happy with how it turns out the first time recorded. If you know your chords well, it really doesn't take long. Maybe a couple of weeks. Some can learn a new song in a day, but that's not me. If it is a song that I know the melody well to, I can usualy play them in a week or so.
You can see all my video covers on http://www.youtube.com/bensonp1000
Call me Pete