There’s plenty of keyword research tools on the web, some of them are listed here. There are free and paid options. If you are a beginner and don’t have too many pages on your website, free options are for you. If you are an experienced webmaster or SEO expert, I am sure you won’t be paying for any of that either:)
Wordtracker – a database of over 330 million search phrases that is updated weekly. It provides the daily stats of a searched keyword as well as up to 100 …

Keywords or phrases are used by the Internet users to find useful websites. When a person enters a search query into a Search Engine (like Google, Yahoo, etc) they expect to be shown relevant results relating exactly to the keywords that were entered. A relevant keyword is a word or group of words that can singularly describe the topic or contents of your web site or page as accurate as possible.
RQs should be able to tell your visitors what your site is all about in general. Having relevant keywords …