How do i add an image under the menu bar and also make it adjust for each device

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?

Thanks in advance.

Mike

URL: http://www.biaccountancy.com