Can you give an url so we can take a look?

did your try adding ?skin=basic or ?skin=custom to the end of the url.

You could check in the skins folder and make sure that your skins are actually there.

since there is a doucle slash in the url, that it not normal.

Check if you putted the base url right.
Look in the file _config.php for this :

 * @global string $baseurl
 */
$baseurl = 'http://www.mysite.com/blog';	// IMPORTANT: NO ENDING SLASH !!!

there can not be an ending slash.

the url to my site is http://even-if.net . Like I said- I used fantastico to install it. I checked the config file which was set up automatically for me.

$baseurl = 'http://even-if.net'; // IMPORTANT: NO ENDING SLASH !!!

I also checked the skins- they are all there.

It looks like it's working now.

Hmmm, yeah, I checked it on my other computer and it seems to be working fine, but on mine, I'm still getting that error. I'm going to clear my history and delete the cookies off my computer- i'm thinking that might be the problem. Is there any reason why it would do that though?

I have had problems with the cookie that lets users change the skin. I disable skin changing on most of the blogs I set up.