You can buy depth stops to attach to drill bits to make blind holes at a certain depth. But for occasional jobs you can gauge depth by using masking tape around the bit at the right depth. Or, as shown, drill through the center of a dowel section, using the bit you need for the hole. Cut the dowel so the exposed bit will be the depth needed for the hole.
Having a trigger-type oil-can close to your drill press is handy when drilling metal. To make oiling more convenient, find a container that will hold an oil-can that you have available. Then cut two small slits in the upper part to accept a worm-gear hose clamp. Slip the clamp strip into one of the holes and out the other. Then wrap the hose clamp around the post of your drill press, about 5 in. down from the upper assembly. Drop the oil-can into the holder. From then on oil will always be just an arm’s reach away.