2) Your seam allowance will partially depend on how thick your fabric is. My really thick fabric needed a 1.5" seam allowance on the width, and a 1" seam allowance on the height. My very first try made the whole thing just barely too short, and that was frustrating. I had only given myself 1 inch or for a seam allowance on the width.
3) Cut two pieces of fabric to the width x height + seam allowance dimensions.
Then, for the pockets, cut two pieces of fabric to the same height, but only 1/2 the width of one cover.
The picture below shows one of each of these pieces cut.
5) Lay out your fabric by laying out one large piece, right side up. On top of that, lay your two pocket pieces, right side up, on the far left and far right edges.
9) Sew around the entire cover, an 1/8" from the edge.
That's it! You are done. Slip the book into the pockets.