Tom Sawyer pretty much summed it up with the dimensions. Mulberry is a really cool wood to work with cause it's so "crisp" and feels lighter in the hand than osage. It may help you to rig up a scribe to get a fix on the ginks as you work the belly down to shape. I use a wooden block with a short tab that follows the back right at the edge of the stave so the crown doesn't effect the pencil line. Along with the tab, I have a pencil that marks the belly and it follows all the waves and wiggles really well. A good base line is a little over 1/2". Once ya get the face shaped, run the scribe along the bow's back, marking the belly line. With it set a tad thicker than 1/2" you should be floor tillered. If your stave is really ginky, be very careful to work the belly flat, following all of the wiggles. Depending on the thicknesses of the rings, when you look at the belly, you'll probably see a drop in a ring at about each third of each limb, but again it depends a lot on the thickness of the rings.
To work the face, some folks mark the sides of the limbs with a straight edge, but on a character stave I like to have the bow follow the fibers, so I'll scrape and carefully draw knife one side until I get a nice flow along that side following all the fibers and around knots. Then I'll scribe a rough a rough width so the bow will be layed out following the flow of the wood. When you run past knots though, you'll need to widen the bow in those areas so you don't cut through fibers. This depends a lot on how wiggly the bow is though.
