I still don't like dreamweaver, but I heard it is better now.
Try to make sure that your images are in the right folder (like they said up there) and that the slashes are in the right direction.
Test on of your images by putting it in the same are as the html file.
Also, you should try to just open a hosting account. Since your experimenting, go for the cheapest. You can get some for a little as 5 dollars a month.
Also, give Brinkster a shot. They have an educational account that is very good and it is free.
http://www.brinkster.com