If you go to "horses" on the top bar you should come to a page that says Visit your barn. Click there. This should bring you to a new page where it says Add Horse. Click on that. Fill in all the info and press save.
You should then be able to click on the horses name and come to their page. Once there, there should be a place to click add photo. Click browse and find the picture on your computer and then press upload.
It should work, but if you continue to have problems let us know.
I think they may need to be in .jpeg format but I'm not sure. If they are not, try putting them in that format and try again.
RusticWildFire: That is what I did and No luck! The files are .jpg and when I put them in and click upload the page goes blank. I have tried with like 10 different photos and have the same luck each time :( any suggestions?