I visited a site the other day that was using something like 15 different meta tags. There were the standard keywords and description, but they also used the author, copyright, PICS-Label, and a bunch of others. The thing is, I wasn't sure whether the meta tags were really all that useful. For the most part they were probably being ignored and only served to make the page take longer to download. In this article you will learn some of the things you should think about before you start dumping tons of meta data on every page of your site. You will also learn about some of the meta tags that do add value and how to ue them.
Read the article: Before You Write Meta Tags