Preheating your stainless steel pots and pans make them nonstick. You ALWAYS want them to be nonstick. Even (or maybe especially!) if you're making something like soup or stew. Is stuff burning to the bottom of your stainless steel pot when you're making stew? It's because you didn't preheat it. Seriously preheat it every time.
Preheat your stainless steel on medium no matter what temperature you're cooking at. You will have to figure out what that means for your stove, depending on how powerful it is. Leave it heating for several minutes at least - there's a water bead test to see if it's ready, where you splash some water at it. If the water evaporates right away, it's too hot; if it sizzles normally, it's not hot enough; if it beads up and rolls around the pan, it's just right. I like to preheat the pan while I'm doing the rest of my prep since the pan itself isn't going to burn.
Once the pan is hot enough, add your oil. Let the oil heat up for a bit and add your food. Once the food is there, then you can adjust the heat to the temperature you want.
Remember to stir what you're making regularly still!