Google +1 is a for making your friends aware about your liking content.
It is more or less like a facebook like button. It will effect the search engine rankings. so Please give it try to your blog or website.
Google +1 is not that much popular, by adding this, we will see traffic increase due to the fact that if someone clicked on +1, their friends see it on google.
here are the steps to add +1 button to your site:-
1.First get the java script code provided by google.
2.the code plusone code can be placed wherever you want the required +1 button.
3.Above script code should be loaded whenever page loads. so you have to places this just like a javasript placement or css location before tag.
To add +1 button to blog:-
1.Go to Design link on your manage blogs in your blogger home page.
2.Click on edit link where you want the +1 button. pop window is show by clicking on edit link
Please let us know if you have any questions.