Here we have a cool werewolf on a sheet of notebook paper. We want the lines of the original image and we want to get rid of those damn annoying blue lines. Here's what ya do. First press Ctrl + Shift + L to run the Auto Levels function. This will brighten up your picture, make the black stand out better, and make the blue lines stand out better, which is actually important.

Now go to Image / Adjust / Hue and Saturation. In the pop up window, you'll see a drop down box at the top that says "Edit: Master". Click on this box and select the Cyan color. Now move the arrow under the Saturation bar all the way to the left, and then move the arrow under the Lightness bar all the way to the right. The saturation turns the blues into grays and the lightness makes the blues turn completely white.

However, since you've only selected the Cyan color to affect, only the blue lines will turn white! If the effect isn't the same on your picture, you may want to try doing the same thing to the blue color, since the lines on your notebook paper are composed of cyan and blue.

See? That's all there is to it. There might be a few blemishes here and there, and you can go and erase or paint over them. I hope this helps you out!