Just a couple years ago I had no idea what SEO really was. But as I started getting more interested in marketing my web sites I really started to focus on getting to the top of the SERPS, especially Google. Some of the sites quickly rose in the SERPs while others took some time and fine-tuning to get there.
I would say I learned most of what I know from forum posts in this forum and other webmaster forums. Also I have Aaron Wall's SEOBook which has been a big help. SEO might be a mystery to some but it really isn't as hard as some make it out to be. I believe in some SEO but I don't like to overdo it. And I have certainly not done any blackhat seo, its all been pure white-hat. And I believe the #1 thing for SEO is quality unique content. That is what my sites are built on, of course with plenty of keyword-rich text.
Anyways, there are a few websites that rank highly for competitive keywords that I am proud of. All of these sites rank in the top 5 at least in Google for their best keyword, plus on the first page for many more. I have developed these sites from scratch using wordpress. Each is in a niche that felt like it needed a quality content and blog site but still had plenty of competition out there. So my advice to you is to pick a niche you like are interested in and just have at it. If I can rank highly for all the top keywords then you can too. Good luck and I hope this inspires you to be #1!