Now is not the time for sitting on our preverbal haunches, there are people out there searching for your product and you can't get into their field of vision if your site is not showing up on their results page. The world of SEO has seen some updates and shake ups, and possible some shake downs. But for the everyman/woman the basic principles remain in place.
Do:
-create keyword rich, good quality, original content
-write good title tags with your primary keyword 50-60 characters
-keep ads below the fold
-monitor your analytics, test and revise
-add new content regularly so Google has something tasty to churn
-build a community on social networks
-make sure you site is speedy and ready for mobile visitors
-link logically within your own site
Don't:
-misuse semantic markup
-create pages with thin content or pages with keywords stuffed in
-scrape content
-participate in linking networks or bother with crummy low quality links
Thanks to Shane Barker for this great infographic guide to SEO ranking factors.