There are three key aspects of SEO. The first one is technical SEO - how your website is built. Second one is content SEO - how the content on your site is structured and what is it’s value. The third one is link building - how your site is being referred to by other pages. Neglecting any of those parts lowers your rating.
This part should be taken care of fully by developers of the site. Most important points are:
- Make sure your page loads and renders quickly - it influences your page rank
- Use Google Webmaster Tools to determine ranking of your site
- Make sure you have a sitemap which shows web crawlers how your site is structured
- Use robots.txt file and tag to point your sitemap to crawlers and store SEO-related logic
- Avoid using flash and informative images, or describe them well for robots
This part should be taken care of by a person preparing content for your site. Main points are:
- Avoid duplicating large parts of content of the page. This is important for titles, descriptions and page content. Pages marked as duplicated go to Google’s supplemental index and are being demoted.
- Title of the page, first heading (h1) and URL should contain key phrase of your page, which reflects content
- Use h2 headings to mark synonyms of the key phrase
- Your content should be relevant with key phrases of your site. If users return from your page to search results, it will lower your ranking
- Link to your subpages only when it’s relevant. Creating multiple links spreads value you’re passing throught links
The more pages with good authority and good diversity link to your page, the better is your own authority and position in search results. Main points to improve your position here are:
- Make sure you get links from popular sites with good authority. Those can be well known journals, or popular websites
- You should be linked by websites with similar content to yours
- Avoid being mass-linked to from just one or two pages
- Never buy links. It’s being detected by Google and lowers your position
I hope this information can help you understand what SEO really mean and what’s about.