The rules of SEO are always changing, but you have to remember that there are a few things that never change. While black hat techniques might work for a short period of time, they are always discovered and action taken against them.
The one thing that does work, no matter what the rules are, is good quality, real websites that offer information that people can use. Well-written content and information is a timeless classic that you`ll find will tend to keep you in fairly stable rankings.
That doesn`t mean you shouldn`t focus on SEO, but remember that making people happy is just as important. If no one likes your site, they`ll just click away and all the SEO in the world won`t help you get more sales. See, there`s more to having a business online than just getting a load of traffic, you need to keep that traffic around, too.
Remember, SEO is important, but you`ll do best if you combine your efforts, using SEO techniques while writing for the people who are visiting your site.