How to add Meta Tags Seo correct

How to add Meta Tags Seo correct on the site should have a general description and keywords to be able to make the site can be indexed by google.

examples of correct Seo Meta Tags

<! - SEO Meta Tags ->
<b:if cond='data:blog.homepageUrl == data:blog.url'>
<meta content='All About Computer, Free Tutorial Internet, News Teknologi, Linux Tutorial' name='keywords'/>
</ b: if>
<meta content='Code 64 Bicth is a blog that contains all the computer tutorials and Free Internet' name='description'/>
<meta content='index, follow' name='robots'/>
<meta content='oBX_jjr202yYp1gMphYTNcoMyms' name='alexaVerifyID'/>
<meta content='Code 64 Bicth' name='subject'/>
<meta content='Code 64 Bicth' name='Author'/>
<meta content='all' name='audience'/>
<meta content = 'general' name = 'rating' /

trying to understand the code would know how, I suggest to make a maximum of 30 words keywords and description 100 words to facilitate google to index your site