That's called exactly what you think it is. It's called a pick slide. Depending on the speed and effects, it makes an awesome sound. You can slide the edge of your pick up the string(s) for varied distances and speeds, including up and back and while fretting. It's usually done with the effect being pushing the pick up the strings - but I've seen people pull it. Wikipedia was wrong, last time I looked. They said it involved 3 or more strings. No, it just usually does - it can involve just one string. Why? 'Cause it's awesome. It makes a glorious noise once you get pretty good at it. The best way to learn is to do. Turn up ALL your volume and pick slide - on every possible setting! Do it over and over again, until you've annoyed the whole house. Each time you do it well, rock it like you're a rock star! If you've got a mirror, stand in front of it and do it - just so you can see exactly how cool it looks! I'm only a little kidding. Crank up the volume. I've forgotten if your guitar has both bridge and neck pickups. If so, select the neck (treble), and turn the volume up loud - you should (ideally) be able to hear it hum a bit. I'm not sure how well your amp will handle it, 'cause this really can sound bitchin' - but that's seriously aided by volume and adding some distortion. You don't have distortion yet. Distortion is pretty sweet!