In the default Blogger.com templates there are no easy way of adding Meta keywords and meta deskription. This is the way to to it:
1. Enter Edit Html in by first clicking your Design-tab and find the row
2. Right after that line of code paste this code:
<b:include data='blog' name='all-head-content'/>
<meta content='DESCRIPTION' name='description'/>Replace DESCRIPTION with your description, Replace KEYWORDS with your keywords and replace AUTHOR with your name.
<meta content='KEYWORDS' name='keywords'/>
<meta content='AUTHOR' name='author'/>
3. Save.
4. Done
