Are you a professional SEO who wants your clients to rank higher in Google?
Read this Google ranking factor infographic.
Being involved in SEO for the past 10+ years, I've read hundreds if not thousands of books, white papers, pdfs, infographics, web sites, forums, etc. I have devoured information on industry tool sites such as Ahrefs, Buzzsumo, Hubspot, Hitwise, iSpionage, MOZ, MajesticSEO, SEMRush, SEOBook, SERPS, SERPBook, SpyFu, WooRank, Raven Tools and many others.
This, by far, has been my favorite, most informative and favorite read. Read it one, twice, three times until the knowledge is ingrained in your skull, it will give you the knowledge, leverage and power to rank any unique formidable content as high in Google as possible.