When I think ‘Google-friendly’ these days – I think a website Google will rank top, if popular and accessible enough, and won’t drop like a f*&^ing stone for no apparent reason one day, even though I followed the Google SEO starter guide to the letter….. just because Google has found something it doesn’t like – or has classified my site as undesirable one day.
The above information does not need to feature on every page, more on a clearly accessible page. However – with Google Quality Raters rating web pages on quality based on Expertise, Authority and Trust (see my recent making high-quality websites post) – ANY signal you can send to an algorithm or human reviewer’s eyes that you are a legitimate business is probably a sensible move at this time (if you have nothing to hide, of course).
The SEO starter guide describes much of what your SEO will do for you. Although you don't need to know this guide well yourself if you're hiring a professional to do the work for you, it is useful to be familiar with these techniques, so that you can be aware if an SEO wants to use a technique that is not recommended or, worse, strongly discouraged.