You have to resize them then, when you're posting a new thread, click on the little paperclip at the top of the text box. Browse for your photo, double click on it and then click on upload. Sometimes it takes a few minutes, depending on your connection speed.
When resizing your photo, set it to height 480 pixels. That will make it the right size for this site. If you need a simple and quick photo editor, I use Photofiltre that I downloaded from Majorgeeks.com. It's free, user-friendly and takes very little computer space.
Can't wait to see the pics!