The definitive guide to using The Important Meta tags

Your title tag provides the caption, your keywords tag provide the scope of the information (and are invisible to humans), and your meta description tag provides the description - together, they form the ultra-important 'hook' of your advertising in the search engines. They are the only meta tags you really need at this time because most search engines at least look at them.

Proper use

• Title - 1-12 words max (with page keyword)
• Description - 5-24 words max (with page keyword)
• Keywords - 3-12 keyword phrases, individually separated with ","
• Meta tags must reflect page content
• Each Page should naturally optimise one keyword (with multiple phrases) and be reflected in the Meta tags.
• Do not spam the search engines!
• Keep it simple - don't obsess about meta tags

Search engines understand one thing: text. They cannot understand graphics or images, and they are still years off properly understanding proprietary technologies such as Flash. Text is the key to accessibility and search engine optimisation - and meta tags offer you a golden opportunity to add a bit more, relevant and descriptive text about your web page into your web page. So, before you even worry about the correct use of meta tags: Write relevant text content for your page! You'll find a good example of meta tags spread at the bottom of this page.

Note: Meta tags are hidden in a document's source, invisible to the reader. Some search engines, however, are able to incorporate the content of meta tags into their search criteria.

Source: http://www.cometsearchenginemarketing.com/