There are 8 main components which determine your ranking on search engines: 
Create useful and comprehensive content that's related to your market to keep your visitors there. Adding keyword-rich text that makes sense and serves the concept of the web page improves your ranking and keeps your visitors interested. The more text, the better for search engine spiders when they index a website, it is strongly recommended that your homepage has at least 200-300 “visible” words. Moreover, the search engine spiders crawl especially the first
20 words of your website so try to keep an eye on them and make them really relevant to what your site is about.In addition, valuable, dense and regularly updated content is one of the most important items you need for your website because visitors who stay longer while visiting a website help measure the popularity of the site in the search engines. Therefore try to put at your homepage such elements, content of which you will change regularly, e. g. news, events, recent articles etc.
It is the most powerful SEO technique you have, so use it creatively! When search engine results are displayed the title is the first thing people see. Thus each page should have a different <title> with 2 or 3 of your keyword phrases at the beginning. The title should explain in a few short words (your keywords) the intent of the page. Don't put your company name first - place your keywords first and if you feel you absolutely must have the company name in the title add it second.
Despite its importance, rather do not overdo it with the length of the <title> tag; 50-80 characters including spaces should be appropriate. And do not just list your keywords, because you then risk being considered as spamming. Rather try to remain as close to a readable sentence as possible. You also should make the title enticing, so that the viewers of search engines listings will also click to see your website.
Below the <title> is a <description> which will be generally the first sentence on at page. The Description Meta tag is also fairly important. Your description should also have 2 or 3 of your keyword phrases at the beginning as so should your first sentence. Just like the <title> tag, reflect the content and try to keep there no more than 250 characters including spaces. Change the words around enough so that you can hit various typings of your keywords.
You should have a different title, description and first sentence on each page. You many also want to try shorter titles with only one keyword or keyword phrase as this will raise you keyword relevance. Also you can consider putting your domain name at the very end of the title.
Although many people incorrectly rely on them when performing SEO, META tags have decreased in importance recently, but are still worth using for clarity and search results. Their initial purpose was to help search engines find out important information about your page that they might have had difficulty determining otherwise.
The Keyword tag is now the least important but is still used by some engines. As you never know when the rules of the search engines will change, or a new engine will want them, so take the time to include these tags in all your web pages. We recommend you do not overdo it with meta tags as well; your Keyword Meta should not exceed 1024 characters including spaces.
If your site especially interesting for a specific geographic location be sure to include the actual location in your keyword meta.When performing SEO, you should always use the same keywords which also appear in the copy of your page, title tag, meta description etc. Any keyword phrases which are used in your meta tags only, will not have enough prominence to help your listings for that phrase.
Having good navigation is important to the indexing of your web pages. There is nothing worse than arriving at a website and having difficulty understanding where to go for the information you are seeking. Have easy to use, clearly marked navigation so your visitors click through instead of click-away in frustration.
Use your keywords both low and high on the web page, keywords should be in the first sentence and in the last one. Keep in mind that for the target audience to find a site on the search engines, the page must contain keyword phrases that match the phrases the target audience is typing into search queries.
The first step before starting your SEO (and PPC campaigns as well) is to make the best keywords list possible. It is a fundamental step that will have a strong impact on your campaign success. Avoid expensive general keywords: you will certainly get a high rate of impressions, but not necessarily high conversion sales. Focus on specific key phrases that will get more highly targeted people to your site.
I would advise you to apply the following methodology to choose the right words:1) Organize a brainstorming with your co-workers, business partners, friends and relatives to find keywords relevant to your business. Focus on the needs of your target audience, what they would type in when looking for your products.
2) Try to make a list of 100 keywords minimum. Providing that you barely reach this goal, do use search term suggestion tool (such as www.inventory.overture.com or www.wordtracker.info).
Yahoo! Search Marketing (formerly Overture) also comes with a keyword suggestion tool, available to Yahoo! Search Marketing advertisers only.
3) Don’t forget dashes, apostrophes, spelling variations, plural versions and paste tense. Your potential customers will not search a keyword in the same way. For instance: website, web site, web-site.
4) Check out your competitors’ webpages for ideas. View the source HTML code and take a look at keywords in their meta tags. They could be a good tip for yours!5) When you are combining your SEO with PPC advertising campaigns, it is very helpful to use tracking results from Google Adwords or Yahoo! Search Marketing to revalue your keyword list. Try to put emphasis on those which gain the highest number of clicks in your PPC campaigns.
As determined by the number, quality and type of linked
pages, most search engines don't even consider web sites if
there is not at least one or two links pointing to the web
site. Links from other popular websites back to your
website are one way of increasing your site's popularity.
Finding websites with similar content (but not your
competitors) and high link popularity, then trading links to
be posted on each site, is one way of increasing your site
popularity.
Get all of your web pages indexed by the search engines by implementing your sitemap. Your web pages should be no more than three clicks away from the home page. On every page you should link back to your home page and your main service(s) or product (s).
This is also important, if you want to get indexed! Text content should outweigh the HTML content. The pages should validate and be usable in all of today's leading edge browsers. Stay away from Frames, Flash, Javascript, Image Maps, and Dynamic URLs, search engines dislike them all a lot.
One prudent tool to use is the “alt” attribute of pictures on your site. You simply describe the pictures and this description can include your keywords. It is essential not to put more than 2-3 keywords to one picture.