Google plus one is new feature from google.
How To Add Official Google +1 Button to Blogger? Try this tutorial !
1.Login to your blogger Dashboard--> Design- -> Edit HTML
2.Click on "Expand Widget Templates"
3.Find </Head> , Use control F
4.Copy below code and paste it just before the </Head>
<script type="text/javascript" src="http://apis.google.com/js/plusone.js"></script>
5.Find <div class="post-header-line-1"> , Use Control F
6.Copy below code and paste it just before the <div class="post-header-line-1">
<b:if cond='data:blog.pageType == "item"'> <div class='post-share-buttons' style='float:right;margin-right:10px;'> <g:plusone size="medium" count="false" expr:href="data:post.url"></g:plusone> </div> </b:if>
Set Right or Left position !