Problem: Images within Theme will not load.

I just started out with WordPress today. I’ve tried to locate an answer to my question elsewhere, but I just can’t figure it out. I hope I don’t sound like a moron.
None of the themes I download and apply will display images in the layout. I really can’t figure out whats going on. All of the images within the theme are broken- regardless of which theme I use. I have been staring at the code for hours, I’ve checked and re-checked and I’m 99.9% sure its not the coding that is the problem.
WTF?!

If you know the answer to my problem, I would really, <i>really</i> appriciate your help!
Thanks!!