i'm really finding it difficult to resolve the permission issues - after three attempts, I now have a working installation under Ubuntu 13.04 as per this page's instructions https://help.ubuntu.com/community/WordPress.
I have also managed to paste the plugins and themes and activated them, which was quite an adventure.
I am trying to import media via the upload function in WordPress. It all works but none of the pictures show, i.e. they appear under Media Library but with the missing picture image. I also note that there is no upload folder under wp-content, which seems to suggest that wordpress is unable to create it. However, I have entered the following in the wp-content folder:
sudo chown -R www-data wp-content sudo chmod -R 755 wp-content
Can anyone help?