Hello i want know if the keyword that i use and choose for my web site are the best and there going to give me the best results......
If you want to know that your chosen keyword is effective for your website check your Google Analytics account and track your site's behavior like location, keyword use to find your site, service provider, bounce rate, and so on.
Keep a close look on the keyword ranking you can use webmeup or majestic seo tools to keep a close look.
To check if your keywords are actually working, try getting your ranking at ALexa, they tell you which keyword is getting high hits on your blog
In addition to using Google keyword Planner, ask your followers on the social network that you are most active for the words they will use in searching for your business. Also, look on the website of your competition for keywords that work for them. All the best.