Reference links only working on homepage

Hi guys, so I am building a custom theme for a client. I have done the css and it all works great, everything is perfect on the homepage, however, when I go to another page (a post, archive, etc.) The page begins to break, like the images links, stylesheets in the css folder, etc. It is referencing the same files (sidebar) but on the home page they work, and others the reference links wont work. How do I get the links to work on both??

Please help asap.

Thanks so much,
Josh