Use Brooklyn Botanic Garden's Christmas Tree Key to help you learn what species you've got.
This tool is what is known by botanists as a dichotomous key. You will be given a series of options in pairs with descriptions and illustrations of each. Click the option that best describes the tree you are trying to identify. Once you do, you'll be given another set of two options. Continue through the series. When you've identified enough characteristics, you will learn what kind of tree you have.