You will need to resize your pic's Abbey.
You can usually do this in the editing software that came with your camera or you can get a free resizer by googling photo resizers.
A good "Free" editing program that has this ability as well as some other good basic stuff to work on your pic's is Picasa.
Picasa 2
Most photo boards limit the size to 150kb and no more than 800 pixels on the long side....
I tried to look up the size limits for here, but seem can't find them....hopefully Will will jump in and give us the limits.
Don't give up....it's not that hard to do and if you need more help just holler.