I was reading this tutorial from the DNN website http://www.dotnetnuke.com/Community/Blogs/tabid/825/EntryId/2675/DotNetNuke-Skinning-101-Part-2.aspx
I found the tutorial to be very useful, however there was an issue when I tried to apply the CSS style. For example after adding the content pane in the initial index.html I have no idea where to place the CSS. If I add it to the head section then the parser will remove it. Where could I add or reference the css file on for the skin? thank you.
Not a DNN specialist, but:
A skin normally contains a stylesheet file called "skin.css" in the skins\skin-name folder.
The reference to this stylesheet is provided for you by the DNN framework.
To reference multiple CSS files, or to add css files with different names, you normally @import them from the skin.css file.