How to Add Floating Share Buttons to WordPress Without a Plugin
1. Go to Appearance > Widgets
2. Drag the Text widget to your sidebar and paste the code below in the text area
<!–SideBar Floating Share Buttons Code Start–>
<style>
#pageshare {position:fixed; bottom:15%; right:10px; float:left; border: 1px solid black; border-radius:5px;-moz-border-radius:5px;-webkit-border-radius:5px;background-color:#eff3fa;padding:0 0 2px
0;z-index:10;}
#pageshare .sbutton {float:left;clear:both;margin:5px 5px 0 5px;}
.fb_share_count_top {width:48px !important;}
.fb_share_count_top, .fb_share_count_inner {-moz-border-radius:3px;-webkit-border-radius:3px;}
.FBConnectButton_Small, .FBConnectButton_RTL_Small {width:49px !important; -moz-border-radius:3px;-webkit-border-radius:3px;}
.FBConnectButton_Small .FBConnectButton_Text {padding:2px 2px 3px !important;-moz-border-radius:3px;-webkit-border-radius:3px;font-size:8px;}
</style>
<div id='pageshare' title="Share This With Your Friends">
<div class='sbutton' id='gb'><script src="http://connect.facebook.net/en_US/all.js#xfbml=1"></script><fb:like layout="box_count" show_faces="false" font=""></fb:like></div>
<div class='sbutton' id='rt'><a href="http://twitter.com/share" class="twitter-share-button" data-count="vertical" >Tweet</a><script src='http://platform.twitter.com/widgets.js' type="text/javascript"></script></div>
<div class='sbutton' id='gplusone'><script type="text/javascript" src="https://apis.google.com/js/plusone.js"></script><g:plusone size="tall"></g:plusone></div>
<div class='sbutton' id='su'><script src="http://www.stumbleupon.com/hostedbadge.php?s=5"></script></div>
<div class='sbutton' id='digg' style='margin-left:3px;width:48px'><script src='http://widgets.digg.com/buttons.js' type='text/javascript'></script><a class="DiggThisButton DiggMedium"></a></div>
<div class='sbutton' id='fb'><a name="fb_share" type="box_count" href="http://www.facebook.com/sharer.php">Share</a><script src="http://static.ak.fbcdn.net/connect.php/js/FB.Share" type="text/javascript"></script></div><br/><div style="clear: both;font-size: 9px;text-align:center;"><a href="http://www.tripozia.blogspot.com/2012/03/adding-floating-share-buttons-to.html" target="blank"><font color="black">[Get This Now]<font></font></font></a></div></div>
<!–SideBar Floating Share Buttons Code End–>

3. To make the buttons float to the left, find right:10px; in the code and change to left:10px;
4. Just save and view your blog to see the buttons appear.
You can style the share buttons by changing the background color and other things. To change the background color, simply find and replace #eff3fa in the code with your own color code.
For Blogger users, You can check this post – Floating Share Buttons To Your Blog’s Sidebar