[SOLVED] Full width header with fixed width image and background color

First of all, hello all and thanks for helping through this website. I am currently volunteering in Cambodia and since i have done some print design, my boss apparently thinks me qualified to manage our website at www.bsda-cambodia.org. Having almost no prior experience, i taught myself a couple of usefull things, but am not able to solve the issue implied in the title. What i basically want is a header layout similar to the one on www.hypem.com, with a picture and a background color of the same height that adjusts itself to the browser width. I have looked for this online but apparently havn't found the right combination of words :-). All help is greatly appreciated.