You can change a button's size only if there are
no images in the button. If there are images,
then the button's/panel's size is controlled by
the image size. You will need to save the images
to the hard disk, edit, and reload them to change
the size.

You will find that you will most likely need to
pick up image editing as well to develop really
nice looking PCFs. Some of us use Paintshop Pro,
some use Photoshop, some use CorelDraw, other
use GIMP, LviewPro, or MSPaint.exe. Different
tools have diffenrent complexities and different
prices as well as features.