This probably one of the better overviews of SEO I have seen in a long time
Very good practical common sense approach to SEO
Surprise one of his main points are:
Make sure your website loads fast!!
Make sure it is setup correctly for SEO
Make sure your website is mobile friendly/responsive
You have to do this before you do anything else. We say this all the time, no point pouring more water in your damn when it is full of holes.