use logo image for header

Hi!
I would like to use my logo image as my header, instead of text. I would also like the menu and social icons to be on the top right, in line with and next to the header, just like the example on the preview/download the theme page (http://wp-themes.com/wp-content/themes/customizr/screenshot.png). how do i move the menu in-line with the header and how do i upload an image for the header bigger than 250 x 100 pixels? can it be long and skinny like text — maybe 350×100 pixels?
thanks!
Aliya