While machinists' lathes require operators to make accurate adjustments and monitor quality, the wood lathe depends upon manual skill and proper technique. The purpose of the several types of wood lathe cutting tools is not obvious at first glance. Learning about them must involve actual practice in the correct techniques.
The first technique you'll need to master is sharpening, not wood turning. Grinding an accurate bevel and touching it up with a honing stone is something you'll repeat a hundred times a day. If you get it wrong, the results will be rough work and accidents. A good sharpening system is a belt-driven double spindle with medium and fine grit wheels. Run it with a 1725 rpm quarter-hp motor, and lower the speed with stepped drive pulleys.
The wide roughing gouge, ground straight across, quickly reduces a squared or irregular work piece to a cylinder. Spindle gouges, ground in a fingernail shape, cut hollows. Enter the work with the bevel raised high and lower it carefully until it cuts. Use the right side of the bevel for a left-hand slope and the left-hand side for a right-hand slope. Never push the gouge straight in or it will bury itself and possibly ruin the work.
Skew chisels yield some of the best and most efficient results of all the turning tools but are tricky if pushed to the limit. When cleaning up a cylinder or a convex curve, lower the side of the blade until the bevel touches the wood, and raise the handle until the center of the cutting edge contacts the work piece. Guide the tool forward with the lead hand. To clean up and square a vertical edge, place the long point downward on the tool rest. Cant the tool slightly away from the work and lower the point smoothly down the face of the work piece in a cleaving stroke.
Parting tools divide the work piece from the waste and leave a rough surface behind. It's a good practice to part down about halfway and then clean up with a skew chisel. With experience a good turner can leave a clean surface nearly through the piece. A quarter-inch parting tool cam also cut a cleanly rounded bead by leading the cut with one corner of the bevel.
The best way to learn is to start with short pieces of waste four-by-fours and practice in succession with each type of tool. Rough down the four-by-four to a cylinder, practice cutting hollows with the spindle gouge, and learn to plane and cleave with the skew chisel. Parting off is the easiest trick but parting a clean piece of work is a skill that's slowly acquired.