Choosing the right keywords - by 'right' we mean profitable - can be a daunting task. Fortunately there are some great tools available to help, some of them free, that can help. Nothing beats good old brainstorming though. Apply imagination and use the links to some of the best free keyword sites listed at the end of this article
The objective is to great your paged ranked at the top for your keywords. Simply picking some keywords and putting them all your pages is not a very good strategy. Instead take the opportunity to every page on your site to test out a different keyword phrase. When you track your traffic, you will soon know which phrases work the best.
Be mindful that the more generic a search term, the more competition there is for that term. So if you're selling toasters and you select the word 'toaster' you'll find over 3,350,000 searches per month with 100% advertiser competition. The specific you can get, the more likely a term is good. The term 'toaster single slot' had 1,300 search and less than 30% advertiser competition, a much better choice.
Don't forget to check what your competition is doing. Analyse their pages for ideas. They may be doing something you haven't thought of.
Here's some tools to help you get the keyword phrase that pays.