Google has provided a very simple page to give you the javascript to place on your page:

http://www.google.com/webmasters/+1/button/

Just to give you a good idea of what its like, think about the Facebook like button except that its collecting information in order to give you relevant advertisements based on things you are actually interested in. It doesn’t currently help you SEO to have higher +1’s but we wouldn’t be shocked if Google starts using it in the SEO calculations in the future.

Here is an example of the code and what it would look like on your site.

[code]
<!– Place this tag in your head or just before your close body tag –>
<script src="http://apis.google.com/js/plusone.js" type="text/javascript"><!–mce:0–></script>

<!– Place this tag where you want the +1 button to render –>

[/code]

Or for a more in depth look at the Google +1 Button, visit the complete documentation set at: http://code.google.com/apis/+1button/