Search engine optimization (SEO) is frequently described as being the most important factor affecting search engine rank and whether or not your pages actually make it into the search engines. It's not. The most important factor is... content. Content, content, content.
Each Web page should have enough unique content to make it worthwhile but not so much as to lose interest in your reader or make them click away. Also, be specific in what you write but always remember: your site is for your visitors. Design it for them first, then the search engines.
The next most important part is the <title> of your page. Again, be specific in what you set it to. For example, rather than having "Windows Tutorial" put "Windows XP Background Services Tutorial".
Finally: meta tags. You do not actually explicity need any meta tags whatsoever. However, many of the top search engines use the "meta description" tag to give the page a short description, rather than extracts from the page. For example, a meta description for Retect might be:
<meta name="description" content="Free web hosting with 100–300 MB disk space and 1–3 GB transfer. CPanel and Fantistico included."/>
To summarize: the most important element is useful and worthwhile content that people actually want to read. Nothing else. Then you should make sure your <title> accurately but concisely describes what the page is about. And, finally, you may add a <meta> description tag for elegant display purposes in the search engines' results pages.
If you develop pages this way, without trying to "cheat the system" by adding unnecessary links, excessive keywords blackhat methods, you will increase your traffic because people will simply want to visit your website. Soon after, people will start linking to your pages. Inward links to your site are valuable and not only increase the number of visitors you get but search engine rankings too.
I hope this short guide has shown you the basics of designing clean, friendly pages firstly for your users and secondly for search engines. Remember: content is everything.
Never argue with an idiot; First he takes you down to his level and then he beats you with experience.