Remove the jaws and route the edges that you could not route while they were still attached. Then use a roundover bit on all of the corners except the inner edge of the inner jaw of the end vise. Give everything a lite sanding, and apply Danish oil to the inner surfaces of the jaws. (By "inner surfaces", I mean those surfaces that will not be accessible when the vises are assembled - the inner surface of the inner jaw, that bolts to the bench, and the outer surfaces of the outer jaws, that bolt to the vise plates.)
My advice? Don't do this. If you have jointer and a planer, use them. If you don't, seriously consider using dimensional lumber that has already been planed and sanded. If you are going to try to clean up construction lumber by hand, using a hand plane is a lot faster and more pleasant than using a belt sander. Except, of course, that to do a good job of planing a board you need a solid bench to hold the board, and you don't have a bench, yet.
A shed is a great project to earn your sawdust legs on. It is just some very basic carpentry skills. You could build the whole thing with a circular saw, hammer, utility knife, pencil, and tape rule. Find a friend or relative that has some decent skills to help. You could do it in a weekend. Keep the size on a four foot increment to minimize wastee. I would recommend a 12 x 12 or a 12 x 16 if you can. If you don't want to cut any rafters (which is really a simple process), you can order small triangle shaped trusses for the roof from your local lumberyard. If you are using T1-11 for the sides, get the real plywood based stuff, no waferboard. Same thing for the floor, use plywood (treated if you like). Cedar for the trim, not pine. The visqueen underneath is a good idea. Insulate the walls inside to help temper temperature swings. Build overhanges into the roof all the way around, 12" is nice. These really are a fun project. You can add a small window with a flower box underneath to make it look a little homey too.
The Cape Ann Shed was designed with coastal New England in mind. So yard work may feel like you’re actually on vacation. From Cape Cod to the beaches of Maine, you will find a Post Woodworking Cape Ann shed adorning the yards of thousands of homes. It’s a popular style with our customers – whether they make their home by street or by sea. An affordable choice for an outdoor structure, the Cape Ann brings functional elements with nautical appeal.