This jig quickly straightens edges
Attempting to rip a straight edge onto a board with irregular edges can be dangerous or downright impossible. One solution: Tack a straight board to the irregular board with finishing nails. Unfortunately, this method leaves small nail marks in the top surface of the workpiece.
Construct a carrier board from 3⁄4 " plywood to a width and length to accommodate most of your boards (14"x7' works for me). As shown above, you can quickly clamp the workpiece to this carrier board, then rip one edge. Remove the workpiece from the carrier board, place the jig aside, and position the just-ripped edge along the fence to straighten the other edge.
—Thomas Bruzan, Des Plaines, Ill.