I had to post a number of pictures of people professionally taken that were Portrait rather than Landscape. When loaded, without any changes, then they were displayed at the top of the Facebook wall with just the eyes or perhaps the eyes and nose showing rather than the whole face.
I used Adobe Photoshop to make my corrections (apologies if the menu options are different on your software). Here’s the simple workflow.
1) With the Portrait picture loaded set the height to 680 pixels, remember to keep the proportions the same, you’ll then probably have a width of about 480 pixels
( Image -> Resize -> Image Size and then set Height to 680 and have Constraint Proportions box checked)
2) Now select option to alter Canvas size; and then set width to 970 pixels
(Image -> Resize -> Canvass Size and set measure to pixels, keep the Anchor centered and set Width to 970 pixels)
3) Now you have the picture with white space at each side; and save it and load it up to your Facebook Fan page.
And for Landscape I used the same methodology to set the Height to 680 pixels keeping the proportions the same and then adjusting the Canvass Size up to 970 pixels.