Q: what is the best way to find out the # of people searching for a specific keyword(s)?
A: My preferred tool is Wordtracker. Note that it will give you an estimated number of searches done per day, which is based on the number of searches done over the past 60 days on the search engines Metacrawler and Dogpile. Thus, you are getting an extrapolation which is not anywhere close to being accurate. Also bear in mind that it is the number of searches done, not the number of people. So 1 person could go 10 pages deep into the search results and that would count as 10 searches.