css template frame help

We are redesigning our site and I am having trouble creating a skelaton frame/template. Our template is pretty simple and straigtforward. I know how to manipulate css but I'm clearly missing some fndemental knowledge when it comes to creating a frame from scratch. I am attaching the layout we want (ignore the background colors - that's just for illustrative purposes) as well as the 2 html template files and 2 css files we have so far. I can provide additonal info/details as needed but basically we need someone to adjust the attached css files to make the frame/template work correctly ie: all parts stay within the wrap container, footer stay below the main section regardless of how long the main section is for a specific page, etc. I think for someone who knows what they're doing this will be a pretty quick and easy job! Thanks