Here are some very good keyword research tools that helps you alot.
Google Keyword Tool - Search for keywords in over 50 languages. It features a very high quality, clean and frequently updated keyword database, with estimated search volume. The down side – keywords that don’t meet Google’s search volume criteria don’t make it to the database, rendering this tool useless for long keyword phrases (four to eight words in length). Regardless, this is one of the best keyword research tools.
Wordtracker – Their free tool has a limit of 100 results. If you want to see all keywords, you must pay. Its free database is very detailed, so in most cases 100 results is enough. Wordtracker gathers keyword data from two meta search engines – Dogpile and Metacrawler. Both search engines hold around a one percent market share, so to estimate real search volume numbers across all search engines you must multiply Wordtracker numbers by 99.
Keyword Discovery - This tool has a noisy database, so use it with caution. It gathers data from toolbars installed on many computers. I find their free database needs a huge clean up.
Yahoo Search Marketing – Follow these steps to get to Yahoo’s keyword research tool. When you click on the link, you will get to a page that says: “Start Advertising with Yahoo! Search Marketing in 5 Simple Steps.” On the right side, select your “market” and “time zone,” then click on “Get Started.” You will see Yahoo say: “1. Target Customers by Geographic Location.” Leave everything as is and click on “Next: Keywords.” You now have access to Yahoo’s keyword tool. There’s no need to register further. Copy your keywords when finished and close the window.
There is a big down side to using this tool; you have to go through this process every time. If you don’t like the hassle, you can pay Yahoo $50 to open an account with their pay-per-click service.
SEO Book Keyword Research Tool – This tool gives exactly the same results as Wordtracker (above). In fact, its database relies on Wordtracker. What you will like about the SEO Book tool is all the extras that come on top of regular keyword research. You can search Yahoo Suggest, Google Suggest, Google Traffic Estimator, Google Insights, Quintra, News Search, Directories, Blog Search, Tag Search and more, all in one place. Play around with it a little.
Now you know where to find keywords. To find more, search with “keyword research” or “keyword research tool” on search engines.