Same principles that goes to blog post commenting, also goes to forum marketing. Very simple - just try to genuinely get into discussions, share your opinion and help people. The great thing about forums is signature. You can add link to your website that will be shown below each of your replies and threads. This is another way to directly drive natural traffic to your website and build up backlinks for SEO at the same time. Look for forums that may have participants who could be interested in your online business. Niche forums are the best choice. Good example is Warrior Forum for internet marketers.
Use social media. Build a presence on social media networks like LinkedIn, Twitter, Facebook, Google+ etc. All of these activities help to get your name out and website address out on the internet. Read about how we doubled our social media audience in a week. Add share buttons to your site to make it easy for people to share your content. And write content worthy of sharing.
Google is currently been inundated with reconsideration requests from webmasters all over the world. On public holidays the Search Quality teams do not look at reconsideration requests. See below analysis. From my experience it can take anywhere from 15-30+ days for Google to respond to reconsideration requests; during peak periods it can even take longer.