"Keywords" are the words that are key to finding information. Most often, these are nouns (person, place, thing) and adjectives (which describes a quality related to the noun it modifies).
Naturally, to find information on archaeoastronomy-related topics, you may well use "archaeoastronomy" as one of your key words. But it isn't always that simple. Consider this: another widely-accepted spelling of archaeoastronomy is archeoastronomy. You may need to use both spellings to uncover the information you need.
Of course, archaeoastronomy is a multi-disciplinary field of study. For this reason, add the following to your bag of keywords:
"landscape archaeology" or "landscape archeology"
astroarchaeology or astroarcheology
Whatever you do, stay clear of astrology and its related terms. Although it sounds similar to astronomy, and seems to have something to do with heavenly bodies and their movements (and I don't mean watching angels on the dance floor), astrology is a totally separate topic from any kind of astronomy, which is what you're doing in this class.
More on Keywords
Since you will research a particular topic, you will also use words that describe that topic. In this case, you might use the names of cultures or peoples, names of places, or names of eras as keywords.