To allow viewers to share your web content via ShareThis:

1. Go to http://sharethis.com/publishers/get-sharing-button
2. Select the 'Website' Button, the ShareThis Style under 'Pick Your Style', and the Oauth Widget. 
3. Click 'Get the Button'
4. Register or Sign In if you already have a ShareThis Account

To allow viewers to share your web content via AddThis:

1. Go to www.addthis.com.
2. Click the 'Get AddThis' button located in the middle of the page.
3. Register to create an account or click the x in the upper right hand corner to abstain.
4. Select 'Customize' in the Preview section on the right side of the page.
5. Select 'more options' the Style menu on the left side and choose how you want the AddThis icon to be displayed.
6. Copy the code that appears to the right.
7. Return to the Administration Console for the Content Box you created earlier.
8. Turn off the Toggle WYSIWIG Editor (uncheck the box), remove any default text.
9. Paste the Code into the text box and click Add Content.

That's it! Feel free to adjust the button's position on your page via Sort Content.