Abstract: A guide clamp (15, 80) has a channel shape which receives the first edge of a board and which forms a straight edge (31, 87) to be slid along a saw fence clamp (23) while cutting the board along a straight line (55, 56) with a table saw (11). A top arm (27, 82) of the channel includes clamping members (35, 89) which clamp the board in the guide clamp while a bottom arm (29, 83) of the channel supports the first edge of the board a fixed distance from a table surface (19) of the table saw. A separate shim (17, 96) is positioned between the opposite, or second edge of the board and the table surface to hold the second edge above the table surface said fixed distance so that the board remains level during cutting to make a true cut on the board.