Place the jointer fence square to the table. This can be done by setting a square on the table and against the fence. Majority of the jointers have a handle or knob to locate. Ease the handle, align the fence and tighten the handle once again. After that, make the depth of the cut by moving the adjustment handle. There might be a knob that opens the changeable side of the table and another one that adjusts to place the depth of the cut. The height of the in feed table will tell you the depth of the cut made. This should be around 1/16 of an inch.
Put a piece of wood through the jointer in such a way that the direction of the grain is from the top to the bottom of the surface. If it is angled upward or reversed, the blade will be able to make a rough cut or possibly cut off some of the wood. See the edge of the board with a square to confirm that the fence is at a right angle to the table. Change the depth of the cut to your requirement.
Grab the edge of the board on the table and press it tightly against the fence. Force the board into the cutting blades. Put pressure on it so that the edge of the board and out feed table stay together. Have a push stick or push pad for small stock so that you do not get your hands injured. Raise your hand as you come near the blade, and hold it again past the blades, once your hands are safe. Then finish the cut keeping the board against the out feed table.