Search Engine Forums, SEO Forum

I want to know about many keywords which are used in search engine optimization.
And also want to know how these keywords are used?

Basically keyword selection depends on the website like if you have car finance website then some of the keywords are like "car loans" "car finance" and so on.

Having a website of reviews of best coffee maker, best vacuum cleaner etc. What sort of keywords or keyword phrase do i use in SEO for this website. Long tail or short keyword is better. I am new to SEO and started on working two month before.