My personal advice would be to study on-site/on-page SEO first.
The best way to do this is to reverse-engineer the biggest sites in your niche.
Like for me, I'll go to Copyblogger and take a look at their source code... how do they layout the page, what heading does the title use? H1/H2? Where are the main keywords seen? Are they in the meta-description/title?
Etc.
This is the hard, but "real world" approach to learning on-page SEO by experimenting and learning from already ranking sites.