select the page where you want to add the page tab
The new tab will appear on your fan page.
Here you can set the tab settings according to your preferences. You can add an image to the custom tab by clicking on Change Tab Image (size of image 111px x 74px)
For Pinterest it is better to redirect the tab to your Pinterest account URL. So for that click on Redirect in Page Source & type in the URL http://pinterest.com/accountname or http://pinterest.com/accountname/boardname
Click save and then scroll to the top and select view tab.