Hi welcome to ECF, I'm sure you'll pick up the information you need. Are you wanting to know about different KINDS of coils (like higher or lower resistance) and their relationship to wattage, or how generally to decide what wattage to use with a particular coil (if so the manufacturer lists the coil resistance and recommended wattages right on the coil, it can be a sort of reasonable "range so to speak) different types of coils, how to figure out wattage etc, these are all questions that I'm sure you will get answers to, if you can get a bit more specific.
Welcome to ECF.
Anna