Keyword research is relatively simple – you can undertake basic research at http://www.thetoolman.net/keywordtool/research.php

Once you've found a profitable overall keyword, you'll need to check out your competition -

http://inventory.overture.com/d/searchinventory/suggestion/

You can place that information in a spreadsheet for reference – or use programs like article architect to extend on your research (affiliate link for article architect)