For headphones you need to decide if you want closed or open, first of all. Open lets sound in and out of your surroundings (you'll hear people talking and they'll hear your music to a degree) and closed isolates, keeping the music to yourself. Once you have that decided, your options narrow, and it will be easier to make decisions. You then need to make a list of what you are looking for, and find the proper terminology, and read reviews comparing to your list. Some headphones may have some things you want and others may have other things you also want that the first ones don't have. That's when you need to decide what is more important to you, and what would work the best for you or appeal the most to you. Make common sense decisions, eg. don't buy open headphones if you know you'll be taking the subway or don't buy big headphones if you know you'll be walking around downtown. Once you've done your research, if you need some help with what certain things mean and how they apply to you and your uses and preferences, by all means ask us here. We can help you a lot more if you have some specific requirements already or if you have some options already picked out.