^^ That would be off site SEO.
On site, you mentioned plugins... use SEO Platinum so you can easily provide a custom Meta Title & Description for each individual web page and post.
Make sure each URL is SEO friendly. (Customize your permalink structure and go for longer titles, think 8+ words.)
Use anchor text when linking between pages for user friendly navigation. Obviously you want to make sure the content on each page and post or article has optimal keyword placement (don't worry so much about density unless it is too high to read naturally, that's the best test) but more importantly make sure each page/article has engaging content that will keep readers interested. A higher user engagement is something search engines reward too.