Choose one of the following links to get a full-sized view of the picture you want in the resolution you want.
Right-click on the selected image and a drop-down menu will appear.
Pick the "Set As Wallpaper" or "Set As Background" option (Opera users should select "Use image as ->" then "Desktop background" option).
For better effect, use brick-color scheme (to do this: if you have WinXP, right-click on your pulpit, pick "Properties", activate "Appearance" panel, pick "Windows Classic" from the "Windows and buttons" list and "Brick" from the "Color scheme" list).
You can also download all the pictures zipped in one package (above) in the resolution you want. Change them every two months in order to have up-to-date calendar information on your desktop.
Do it manually (in WinXP, chose picture file in Start > Control Panel > Desktop > Appearance and Themes > Display > Browse - more on www.microsoft.com) or download small freeware program - from www.desktopchanger.com - which will do it for you.