Hey Brown. Here is what you do. Sign-up for at a free photo-hosting website such as photobucket.com, upload your photo to that site, then you can post the pictures on here as large as you want without having to bring the size down.
A real quick and easy website to use is photolava.com....just download your picture on there.....copy the "image location" by right clicking with your mouse on the picture then copying image location. There is no sign up on this site I believe and you can just upload your pic real quick and use it in seconds on this site by "copying image location".
Once you make a post on here, click on the yellow mountain looking icon on the right hand side of the window of the post. Then insert the image location you had saved previously in that box. It will then post the pic in the post.
Posting Images
photobucket is the easiest and its free 
