Of course, you will need to have a StumbleUpon account first of all.
On your blog (or any blog that has the StumbleUpon widget installed), click on the StumbleUpon link (widget) on the page that you want to have added to your Facebook fan page. If you do not have the widget installed on your blog, go to the "design" link on the top right side of your blogger page. Once done, click on the "layout" link that you will find on the left side of the page. From there you will have to look for the StumbleUpon widget. If you type in StumbleUpon in the search section, you will be able to find the widget quickly.
Now you should have the page up on your screen that you want to Stumble, and the StumbleUpon widget installed on your blog (if you are doing this on your own blog!). Note: you can only do this on a blog that has the StumbleUpon widget installed. Click on the StumbleUpon widget. You should see the screen below. On that screen, click on the "F" link under the word "share".
The next screen you will be taken to will be the one below. Click on the "On your own timeline" choice from the drop down menu. Once done click on the "On your page" link. And you have now successfully added your Stumbled blog page to your Facebook fan page.
Below shows some of our stumbled blog pages posted to our Harrach Glass fan page.