^^ Lol tis okie, I had to ask my friend how to do it when I first came here too. When you click on account, go down to click on settings. once the general settings loads click on my layout. if you want to customize it yourself, find a color in the pick and drag the icon of it down to parts that say back ground color or wherever you want that color. for a picture background get the html link to the picture and at the bottom of the page is a box to put it in, then click page background below and it should work. make sure you save it too =D
if that was too complicated i can try explaining again o_o;