How do I scan PCB boards, everytime I try the image never comes out clear.

Is there a reason you want to scan it instead of taking a digital photo?

loop a Dark Towel around the outside edges and then put the PCB Board inside the hole in the middle then find something that will cover the whole shebang. just try to make sure their is no light leaks or the image will be under exposed.

I just lay them on my scanner bed and close the lid slowly. I have never had any problems or scratches at all.
~~NGD