One of the things i have noticed in the last couple of months, on most search engine or SEO news websites is the need for everyone with a website to create a blog. I noticed also on a lot of you tube videos with Matt Cutts, is he states that it is a great way to boost your search engine rankings as well as gain valuable traffic.
What i have been doing lately is going to other like minded sites and making useful comments on their sites, this attracts other people to your blog. On most blogs they will ask for your name, email address, website and of course your comment. This provides people reading the comment, with a link to your website or blog and this is a useful way of getting traffic to your site. Post content often and allow visitors to comment. If you allow this chances are that they will come back.
A blog of course isn't everything when it comes to Seo. The same basics must still be applied to your website when you are developing it. For instance, make sure your keyword density is high, don't forget those meta tags, get good QUALITY LINKS, submit your site-maps and of course ping or notify the search engines.