A recent report on the website searchengineland.com describes a new, but as yet unconfirmed, Google ranking update affectionately being called 'Fred'
The article states that "Many of the automated tracking tools currently show significant volatility and fluctuations, which is an indicator of an update. Plus, with all the industry chatter, and with webmasters both complaining about ranking declines and rejoicing about ranking increases, it’s likely that there was a Google update."
For many web designers however, it's hard to keep up with all the changes that search engines make in how they assess websites, particulary Google. Obviously Google is the most widely used search engine in the World so anyone who does design websites for a living has to keep up to date with the latest changes.
However, the basics of SEO tend to remain fairly constant ad the best source to go to for information on how SEO should be implemented, is Google themselves.
With that in mind, here's a link to their SEO guide for anyone who is interested...
https://static.googleusercontent.com/media/www.google.com/en//webmasters/docs/search-engine-optimization-starter-guide.pdf
The full article on the Search Engine Land website can be found here