It's so hard (no pun intended) to explain. First, when you see something sexy or arousing, you feel a rush of blood to your dick, which begins to get longer and thicker, and if you have clothes on the crotch area gets tighter and tighter. As for actually masturbating, think of rubbing your hand up and down a stick of flesh as thick as a somewhat girthy tree branch. The amount of pleasure you get corresponds with how long it's been since you last came. The longer it's been, the better it feels. Some guys have to use lube and some don't; that usually depends on whether your dick is circumcised or not. As you go on and on, it becomes more pleasurable (you usually feel the most pleasure in the head and underside because that's where all the nerves are located) until you reach a point where you know you can't stop without coming. It stays like that for about 1 second and then you come. I hope the length of my response didn't weird you out. I tried to explain as thoroughly as possible because I've always been curious about what it's like for girls, and I'm glad to help explain the reverse and try to provide a bit of insight.