Log in to your Google Analytics account. Locate the website you wish to track keywords from and click on the link for your entire website. Click “Traffic Sources,” followed by “Sources,” next “Search” and finally “Organic" from the gray column on the left. Review the keywords listed on the report.
I would like to explain about Pro-rank track Tool one of the best tool used for tracking keywords. you can get daily keywords report from Pro rank tracker tool
It would be better if you do it manually on your private window because it always gives correct results for the keyword, Although it is time taking but it is an effective way to get an exact rank of a keyword.
The position tracking tool allows you to track your web site ranking for target keywords. Using a good keyword tracking tool allow you to spend less time trying to find keyword statistic and more time analyzing these results. To measure which keywords are driving conversion you need to create a custom report in your googal analytics account.
All the services have limited coverage. Why not to learn your niche better. You will know so many synonyms or specific topics that really worries people.