Newbie Help Required!

Hi all,
I am trying to add a picture under the menu bar of my website, which will adjust on each device.
If someone could tell me the code and where to write it in that would be brilliant!
Also the resource section near to the footer on my home page, how would i go about making this be the same on each page though out the site?
As this is my first website i would appreciate any improvements or ideas that anyone would feel would improve/better my site.

Thanks in advance.
Mike

URL: http://www.biaccountancy.com