Question: How do I find keywords that will help me the most?
Answer: Try getting some background information about your topic first by using CQ Researcher or an online/print encyclopedia. As you read through a broad overview of your topic, start making a list of the words that are used. Sometimes you'll run across other search terms that you may not have thought of otherwise.
Question: What do you think is the best way to weed through results about your topic and narrow it down to the best ten?
Answer: There are some standard ways to narrow down results. You can specify a time-frame (only the last few years, or a specific date range). You can narrow results to a specific location (United States, California, etc.). Sometimes the databases build in ways to narrow your results. For example, in Academic Search Premier, you can look at the left-hand column for a variety of ways to refine your results...by the type of publication, a subject area, etc. Often times if you perform a "Subject" search, you will get fewer, and more precise results as well.
Always keep in mind that the number of results is not the true measure of research success. You want to find the right mix of articles that address the key issues you are trying to write about. Also, the currency of the information you find is important.