I want to try something new... I'd like to play the notes that the singer would sing on guitar, so that the song is instrumental. How would i go about doing this for the cover songs, seeing as how I don't have the music in front of me?
This sort of thing has been done in the past, most notably with bands like The Ventures. It can be a lot of fun, but you'll need to learn to play the song melodies on guitar. Perhaps the easiest way is to learn to hum or whistle the melodies of songs, and then, when you've got that perfect, try to match the notes you're humming on your guitar. It's going to take some practice, and you'll need to train your ears. Check out this lesson on learning to figure out songs by ear.