For this example I'm taking cuttings from a Coleus in my garden that I'm going to recycle as a houseplant this winter. The first thing you have to learn is where to cut the plant along the stem. I've marked the photo of the plant stem above with were the location of the nodes are on the stem. You want to cut, with a clean, sharp tool, just below these nodes. When the cuttings begins to root, it is from these spots that the roots will emerge from.
If you'd like to increase the odds that your cuttings will root and survive you can dip the cut end in rooting hormone that you can purchase at just about any garden center around Chicago. This step isn't always necessary but if you're a beginner at propagating plants go ahead and use a rooting hormone. Once you've dipped your cuttings into your rooting hormone you can gently insert it into a pot with some moist potting soil covering all the nodes, so that roots can develop from them.
How to Care for Your Cuttings
Place your cuttings in a bright location like a south facing window.
Protect your cuttings from extreme heat and cold. Too hot and your cuttings will dry out because there are no roots to take up water. Too cold and your cuttings will rot because there is no warm to stimulate root growth.
It will a couple of weeks for the roots to develop. If you potted your cutting; avoid moving it or pulling it out of the soil so you don't break any of the developing roots. Keep the potting soil moist but not soaking wet to prevent rot or fungus from killing your cutting.