A list of keywords and phrases that is going to be targeted for SEO should be a number one priority. These keywords & phrases will then be what we you can judge the SEO effectiveness over time.
The keywords should be typical words that a user is expected to type into a search engine and find your given website. The phrases should include the keywords and maybe only a few other words.
In choosing keywords you should also consider the spelling, abbreviation, apostrophes, etc. The following table gives just a few examples:
All keywords and phrases should be checked for popularity and search volumes. The following three sites give popularity indication
Don’t automatically go for the highest traffic volume keywords. If you are a small site it may be worth targeting some niche keywords rather the top keywords. The top keywords will undoubtedly have large sites competing for them and its always better to be a “big fish in a small pond rather than a small fish in a Google ocean”. Over time as your site grows you can target the bigger keywords and compete with the big boys.