How to find the best keywords SEO

Find your niche keywords, and get the best search terms than others.Though google not like you to write articles on one key word, but, it’s a good idea for you to generate free traffic, especially from the long tail keywords.How to find the best search keywords?Here are some tools which can help you get more keywords ideas.

Word Tracker
Word Tracker can help you choose the right Internet marketing keywords that will help your search engine placement and ranking. Use Wordtracker for keyword research to learn what keywords and keyphrases your customers are using to find the products or services you offer. Provides basic access for free and a much more robust paid version.
Seobook keywords tool
This keywords tool is based on Word Tracker, but you can get more details about the kerwords on google and yahoo,this tool will provide you WordTracker count, Google daily est,Yahoo!daily est,MSN daily est,Overall daily est ,Yahoo!Suggest,G Trends etc.
Google insights
With Google Insights for Search, you can compare search volume patterns across specific regions, categories, time frames and properties. See examples of how you can use Google Insights for Search.
Keyword Discovery
Discover the right keywords to target on your website and PPC campaigns. Identify common keyword misspellings, seasonal trends, related and industry terms. Run keyword permutations and even translate your keywords to and from various languages. KeywordDiscovery has the largest keyword database of around 30 billion searches compiled from close to 200 different search engines. Offers basic access for free and a much more robust paid version.