Ok, so this post might be a sell out, but since none of the movable type seo advice tutorials I've seen so far do it right I thought it was time for someone (me) to do better. I assume you have done some research so I won't go through the purpose of the meta tags. In this example I will be adding author, keywords and description meta tags.
In your entry template find the line <mtsetvarblock name="html_head"> and add the following lines.
<meta name="author" content="<$MTEntryAuthor$>" />
<meta name="keywords" content="<$MTEntryKeywords encode_html="1"$>" />
<meta name="description" content="<$MTEntryExcerpt encode_html="1"$>" />
Do the same for the page template, but use the variables MTPageAuthorDisplayName, MTPageKeywords and MTPageExcerpt.
The final result should look like;
[Entry template]
<mtsetvarblock name="html_head">
<meta name="author" content="<$MTEntryAuthor$>" />
<meta name="keywords" content="<$MTEntryKeywords encode_html="1"$>" />
<meta name="description" content="<$MTEntryExcerpt encode_html="1"$>" />
[Page template]
<MTSetVarBlock name="html_head">
<meta name="author" content="<$MTPageAuthorDisplayName$>" />
<meta name="keywords" content="<$MTPageKeywords encode_html="1"$ >" />
<meta name="description" content="<$MTPageExcerpt encode_html="1"$>" />
The big difference between my method and most others is that I supply the encode_html directive. This means that if your entry contains html tokens, such as the double quote (") it will be encoded as &qout; inside the meta tags, rather than breaking your html which the " by itself would do.
For the index lists, such as the index page, archives, author entry list and so forth I would recommend using static content for seo. The reason for this is that the MT tags we have just used are context sensitive. So if you used the entry tags in the author list it would only display the content of the last entry for this author due to the context.
Good luck!
