on Just Publishing Advice:
You need keywords for your blog articles or to choose your 7 Amazon book keywords
Whether you are a blogger or an author, or both, you continuously need to research and select suitable keywords.
While the Google Keyword Tool is the choice of many, you need to have an Adwords account to be able to use it.
But Google Adwords is for advertisers who use it to assign keywords to the Google Keyword Planner for their campaign ad groups.
For authors and bloggers, going to all the trouble of signing up for an account, including your billing information, is not worth the effort.
However, there are many free alternatives that you can use to find keywords for the articles you write, or for the Amazon keywords that you need to add to your books and Kindle ebooks when you publish.
In fact, for authors, you should continue to research keywords even after you have published your book because improving them can help increase sales.