WestVa - here ya go
<a href="javascript:window.external.AddFavorite('http://westcollectibles.com/default.aspx',
'WestCollectibles.com')" style="font-size:12px;color:#ffffff;font-family:verdana;">
<img src="http://westcollectibles.com/images/bookmark.gif" border="0" width="174" height="48"></a>
where it says "WestCollectibles.com" inside the parentheses, right after AddFavorite, that's the text that shows up in their favorites list. can change it to whatever you want.
and I dont know if you can do it with the OfficeLive pages or not, but you can create a custom icon for the user to end up with in their favorites. Simply save a graphic in ico format, name it favicon.ico and put it in your root folder on the site. must be 16x16 or 32x32 and color depth of 16, 256, or 16 million colors.
some browsers (but not IE from my understanding, but havent tested it) will allow you to do gif images or png images.
and you can have the .ico file somewhere else besides root folder of site if you put the following two lines in head area of html page (with urls pointing to file location on web)
<link rel="icon" href="http://example.com/favicon.ico" type="image/x-icon" />
<link rel="shortcut icon" href="http://example.com/favicon.ico" type="image/x-icon" />
if using .gif image, the type= would be image/gif instead.
and here's a site that will convert image to .ico format for you http://www.graphicsguru.com/favicon.php