Posting a picture for the first time is often a bit of a challenge. I had difficulties my first time. Sometimes it takes a while. And if there is an error, there is not always an indication to you that there was an issue.
I believe the most common problem is that everyone loves to upload nice quality pictures. Most cameras, and even camera phones support very high resolution. These high quality images are big "files". Often several around 5,000 Kb or larger. (5,000 Kb ~ 5 Mb).
The administrator of the system has conserve space so the largest image size a person can post is 256K. we had more than 12,000 posts so you can see how it an issue. Everything done here is done from donated time and resources. I hope you understand. We would love to see your photo do you know how to make it smaller before you attempt to upload it?
I dug up a few references on the forum on this so you can read them too. Perhaps they will help. Don't give up. If you need more help just ask, I will do all I can to help.
Here are some other threads of discussion on this and a few other tips that have assisted others: