Child Theme problems

Hi,

I create a folder /wp_hot_destinations_child in the theme folder and copy style.css from original theme to that folder.
I tried including complete css code in this css file and also > @import url(“../wp_hot_destinations/style.css”);

Both solutions result in a broken top menu and some other style issues and missing graphs.
Are there any basic instructions on how to set up a child theme for Hot Destinations ? What files need to be copied to the child folder, besides the css file ?

I assume this is used by many people, as upgrading the theme would possibly overwrite changes made in the css etc ?

Thanks.