My first job is related to seo . I read some blogs focused seo and also surf around in webmaster forums like dp to learn more .
Im still learning and so is everyone else, SEO changes everyday in my opinion and there are new ways to use it. I just read blogs and forums to learn.
Best place to learn is your website and others on the internet. Take a competitive keyword and say what did they do to get here and analyze it and compare it to the others. I learned over a period of ten years working for an internet technology start up creating search engine technology for email electronic discovery several years ago. We had to compete on the internet with Microsoft, IBM and several other fortune 500 companies to get leads. We ended up taking the knowledge already know about how search engines indexers and parsers worked in our own software and started applying it to SEO. We ended up getting so good at it we became an SEO company. Over the years we noticed the best way to learn is to think, plan, test,and then execute. Think what data does a search engine gather and how does it gather that information and how can I make my website more friendly to that. The most important thing we learned over the years was relevancy. That no matter what you do to rank if your page isn't highly relevant and have a visually appealing design to what people are looking for it not going to stick in the top 3 for a long period. So its always best practice to get a webpage or site to that point in design before trying to rank. Because the several people end up ranking in top 3 but because there website design or copy is of low quality they are converting a low amount of leads.
This ain't gonna be much help but I learned through a 'Guru'. It's all about contacts and setting your standards high! 'People are your most valuable resources' Antony Robbins