Search Engine Optimization is broken down into two segments. Aspects of onsite changes to make your site more spider friendly and Offsite keyword text backlinking.

From an on site SEO perspective, consistency and placement of your keywords are important. Spider read a page top to bottom left to right. Therefore your major keywords should be consistent from your Meta tags all the way down to your footer page. Consistency in Syntax as well a prominence. Interlinking your site with keyword text links not only helps navigation of your site but it improves your keyword density.

There is much discussion in regard to the keyword density as to what is considered a non spam factor. Each page should have about 350-500 words per page with a keyword density of no more than 7-10%. Keyword density is also considered in your graphic alt text as well as hyperlinks.

Generally speaking, if your keyword looks stuffed, it is.

Basic On site SEO Factors:

Title Tag ( with Keyword)
Meta Description ( Consistent with Title Tag)
Meta Keywords ( Consistent with Title tag and Description)
H1 Tags ( with Keyword)
Graphic Alt Text ( with Keyword)
Keyword Hyperlinks
Keyword Density in body text
Keyword in Menu Links
Footer Page with Keyword Text Links

Off site linking is generally though of as the most effective way to raise in the search engine rankings. However if your on site SEO is not complete you are battling an up hill battle.

When planning your off site linking strategy you need to keep in mind that reciprocal links are considered devalued through the latest round of algorithm updates. Textual Keyword Rich links from various C-block IP address are the best links possible.

There are many ways to receive quality links.

Some of the top linking strategies to receive quality links come from the following venues:

Article Submissions
SEO Friendly directories
Blogs
Press Releases

Growing your links in a consistent manor is also relevant. Creating 1000s of links in a short period of time could set up red flags. You will receive many links via RSS Feeds from the sources described above and be successful in your linking campaign.

Getting Search Engine rankings can take time depending on your keywords, but consistency and effort both on site and off site will bring you the desired results.